# Around

> Around is a knowledge graph published as a website: tools, guides,
> comparisons, worked examples and definitions, connected by typed
> relationships. Every number is computed by tested code; every factual
> claim traces to a named source shown on the page.

Full graph export (nodes + typed edges): https://around.ie/graph.json
Methodology (how pages are made and validated): https://around.ie/methodology/

## Topic hubs

- [Mortgages](https://around.ie/topics/mortgages/): How mortgages work in Ireland: repayments, deposits, borrowing limits, rates and the real cost of a home loan.
- [Percentages](https://around.ie/topics/percentages/): How percentages actually work: calculating them, reversing them, and the traps hiding in everyday percentage claims.
- [Compound Interest](https://around.ie/topics/compound-interest/): The growth loop where interest joins the balance and starts earning interest itself, so growth accelerates over time.
- [Interest Rates](https://around.ie/topics/interest-rates/): Where interest rates come from, who sets them, and how a central bank decision travels to your mortgage and savings.
- [VAT (value-added tax)](https://around.ie/topics/vat/): How value-added tax works, the current Irish rates, and the maths of adding and removing VAT from a price.
- [Inflation](https://around.ie/topics/inflation/): Why prices rise, what that does to the value of money, and how to tell real growth from a bigger number.
- [Time & Dates](https://around.ie/topics/time-and-dates/): How the calendar actually works: leap years, week numbers, counting days, and why the months are the shapes they are.
- [Argentina](https://around.ie/countries/argentina/): Argentina on Around: public holidays, dates and the jurisdiction-specific corners of the graph.
- [Australia](https://around.ie/countries/australia/): Australia on Around: public holidays, dates and the jurisdiction-specific corners of the graph.
- [Brazil](https://around.ie/countries/brazil/): Brazil on Around: public holidays, dates and the jurisdiction-specific corners of the graph.
- [Canada](https://around.ie/countries/canada/): Canada on Around: public holidays, dates and the jurisdiction-specific corners of the graph.
- [France](https://around.ie/countries/france/): France on Around: public holidays, dates and the jurisdiction-specific corners of the graph.
- [Germany](https://around.ie/countries/germany/): Germany on Around: public holidays, dates and the jurisdiction-specific corners of the graph.
- [Ireland](https://around.ie/countries/ireland/): Ireland on Around: public holidays, dates and the jurisdiction-specific corners of the graph.
- [Italy](https://around.ie/countries/italy/): Italy on Around: public holidays, dates and the jurisdiction-specific corners of the graph.
- [Mexico](https://around.ie/countries/mexico/): Mexico on Around: public holidays, dates and the jurisdiction-specific corners of the graph.
- [Netherlands](https://around.ie/countries/netherlands/): Netherlands on Around: public holidays, dates and the jurisdiction-specific corners of the graph.
- [New Zealand](https://around.ie/countries/new-zealand/): New Zealand on Around: public holidays, dates and the jurisdiction-specific corners of the graph.
- [Poland](https://around.ie/countries/poland/): Poland on Around: public holidays, dates and the jurisdiction-specific corners of the graph.
- [Portugal](https://around.ie/countries/portugal/): Portugal on Around: public holidays, dates and the jurisdiction-specific corners of the graph.
- [Spain](https://around.ie/countries/spain/): Spain on Around: public holidays, dates and the jurisdiction-specific corners of the graph.
- [United Kingdom](https://around.ie/countries/united-kingdom/): United Kingdom on Around: public holidays, dates and the jurisdiction-specific corners of the graph.
- [United States](https://around.ie/countries/united-states/): United States on Around: public holidays, dates and the jurisdiction-specific corners of the graph.

## Interactive tools (client-side, deterministic)

- [Mortgage Repayment Calculator](https://around.ie/tools/mortgage-calculator/): See the monthly repayment for any loan, rate and term — plus what overpaying does to the interest and the years.
- [Compound Interest Calculator](https://around.ie/tools/compound-interest-calculator/): See how savings or investments grow when interest earns interest — with a year-by-year breakdown.
- [Percentage Calculator](https://around.ie/tools/percentage-calculator/): Work out X% of a number, what percent one number is of another, percentage change, and reverse a percentage increase.
- [Age Calculator](https://around.ie/tools/age-calculator/): Your exact age in years, months and days — leap-day-safe, with the day of the week you were born.
- [Date Calculator](https://around.ie/tools/date-calculator/): Days between two dates, working days, add or subtract days, and the weekday or ISO week of any date.
- [VAT Calculator](https://around.ie/tools/vat-calculator/): Add or remove VAT at the current Irish rates — or any rate — with the net, VAT and gross laid out.
- [Annual Leave Optimiser](https://around.ie/tools/annual-leave-optimiser/): Where to spend your leave days for the most consecutive days off — computed from each country’s 2026 public holidays.
- [Inflation Calculator](https://around.ie/tools/inflation-calculator/): What inflation does to prices and savings over time: future prices, today’s value of future money, and real rates.
- [Savings Goal Calculator](https://around.ie/tools/savings-goal-calculator/): Work out the monthly amount needed to reach a savings target by a chosen date.

## Guides

- [How much you can borrow for a mortgage in Ireland](https://around.ie/guides/how-much-can-you-borrow-mortgage/): The Central Bank loan-to-income limits, how lenders apply them, and what they mean for your price range.
- [What is compound interest?](https://around.ie/guides/what-is-compound-interest/): A plain explanation of compound interest, why it accelerates, and why it matters for anyone saving or borrowing.
- [How to calculate percentages](https://around.ie/guides/how-to-calculate-percentages/): The three questions every percentage problem reduces to, and how to answer each one without a formula sheet.
- [How much deposit you need for a mortgage in Ireland](https://around.ie/guides/mortgage-deposit-ireland/): The Central Bank deposit rules for first-time buyers, movers and buy-to-let — and what they mean for your budget.
- [Current VAT rates in Ireland](https://around.ie/guides/current-vat-rates-ireland/): Ireland’s VAT rates as published by Revenue — the standard 23%, the reduced rates, and what “as of” really means.
- [How mortgage repayments work](https://around.ie/guides/how-mortgages-work/): What a mortgage repayment is made of, why early payments are mostly interest, and how the balance actually falls.
- [How leap years work](https://around.ie/guides/how-leap-years-work/): The full leap-year rule — including the century exception most people never meet — and why the calendar needs it.
- [How a rate change reaches your pocket](https://around.ie/guides/how-rate-changes-reach-you/): Transmission, in euros: what a quarter-point does to a €300,000 mortgage and what a full point does to savings.
- [What is inflation?](https://around.ie/guides/what-is-inflation/): Inflation is the rate at which prices rise and money’s buying power falls — how it is measured and why it compounds.
- [Mortgage overpayments: how they cut years and interest](https://around.ie/guides/mortgage-overpayments/): Why paying a little extra each month removes a surprising amount of interest, and what to check before you start.
- [The cost of buying a home in Ireland beyond the price](https://around.ie/guides/cost-of-buying-a-home-ireland/): Stamp duty, legal fees, valuation and the other costs that arrive on top of the deposit.
- [How compound interest works](https://around.ie/guides/how-compound-interest-works/): The four moving parts — principal, rate, frequency and time — and how each one changes what you end up with.
- [How VAT works](https://around.ie/guides/how-vat-works/): Value-added tax explained: charged at every stage, reclaimed by businesses, and finally paid by the consumer.
- [Percentage change, explained](https://around.ie/guides/percentage-change-explained/): How percentage increase and decrease work, why the direction matters, and why a fall needs a bigger rise to undo it.
- [What is an interest rate?](https://around.ie/guides/what-is-an-interest-rate/): The price of money: what a rate actually prices, who pays whom, and why one economy has many rates at once.
- [How central banks set interest rates](https://around.ie/guides/how-central-banks-set-rates/): The ECB’s three key rates, the six-week rhythm, and what a central bank is actually steering when it moves them.
- [Reverse percentages: finding the original number](https://around.ie/guides/reverse-percentages/): How to get back to the price before a percentage was added — and why subtracting the percentage gives the wrong answer.
- [The Rule of 72](https://around.ie/guides/rule-of-72/): A mental shortcut for how long money takes to double — how it works, how accurate it is, and where it breaks down.
- [Switching your mortgage: how it works](https://around.ie/guides/switching-your-mortgage/): What switching lender involves, when it saves money, and the costs and checks along the way.
- [Why compound interest makes pensions work](https://around.ie/guides/compound-interest-and-pensions/): How decades of compounding do most of the work in a pension, and why starting earlier beats contributing more.
- [Adding and removing VAT: the maths](https://around.ie/guides/adding-and-removing-vat/): Adding VAT multiplies; removing it divides. Why subtracting the rate from a gross price is always wrong.
- [Counting days between dates](https://around.ie/guides/counting-days-between-dates/): Inclusive or exclusive, calendar days or working days — the counting choices that change the answer by a day or more.
- [Choosing a mortgage term: what the years really cost](https://around.ie/guides/mortgage-term-length/): A longer term lowers the monthly payment and raises the total cost. The trade-off, in honest numbers.
- [Why interest rates rise and fall](https://around.ie/guides/why-rates-rise-and-fall/): Rates move because inflation moves: the steering logic, and why the real rate is the number that decides behaviour.
- [When compound interest works against you](https://around.ie/guides/compound-interest-on-debt/): Compounding applies to what you owe as well as what you save — credit cards, loans and how to read APR.
- [Bridge days: the arithmetic of long weekends](https://around.ie/guides/bridge-days/): A holiday on a Tuesday means one leave day buys four days off. How bridge days work and how to spot the best ones.
- [The compound interest formula, explained](https://around.ie/guides/compound-interest-formula/): What FV = P(1 + r/n)^(nt) actually says, term by term, with a worked calculation you can follow.
- [How inflation compounds](https://around.ie/guides/how-inflation-compounds/): Inflation is compound interest pointed at prices: the same loop, running against your money instead of for it.
- [Percentage points vs percent](https://around.ie/guides/percentage-points-vs-percent/): A rate rising "by 2%" and "by 2 percentage points" are different claims — how to read each and why headlines blur them.
- [Compound interest and inflation: real returns](https://around.ie/guides/compound-interest-and-inflation/): Why the growth you see is not the growth you get, and how to think about returns after inflation.
- [Why central banks target 2% inflation](https://around.ie/guides/the-2-percent-target/): Why the target is low-but-not-zero, what 2% quietly does over decades, and what happens when inflation misses it.
- [Week numbers, explained](https://around.ie/guides/week-numbers-explained/): How ISO week numbers are assigned, why some years have 53 weeks, and why 30 December can belong to next year.
- [Saving monthly vs investing a lump sum](https://around.ie/guides/saving-monthly-vs-lump-sum/): Which builds more: steady monthly saving or a one-off lump sum? The honest maths on both.
- [Why the months have different lengths](https://around.ie/guides/why-months-have-different-lengths/): Why February is short and the rest are a jumble: the Roman calendar politics still printed on every wall calendar.
- [Fractions, decimals and percentages](https://around.ie/guides/fractions-decimals-percentages/): The same number in three costumes: converting between fractions, decimals and percentages in both directions.
- [How tax affects compound interest](https://around.ie/guides/tax-and-compound-interest/): Interest is usually taxable, and tax paid along the way compounds too. How to think about returns after tax, with Ireland’s DIRT as a worked case.
- [UTC and time zones](https://around.ie/guides/utc-and-time-zones/): What UTC is, how time zones offset from it, and why two places can be on different dates at the same moment.
- [Who actually pays VAT](https://around.ie/guides/who-actually-pays-vat/): Businesses collect it, reclaim it and hand it on — the whole chain lands on the final consumer. How and why.
- [Common compound interest mistakes](https://around.ie/guides/compound-interest-mistakes/): The misunderstandings that quietly cost savers money — and how to avoid each one.

## Comparisons

- [Fixed vs variable mortgage rates](https://around.ie/compare/fixed-vs-variable-mortgage/): What each rate type actually promises, the trade-offs, and how to think about the choice without predicting the future.
- [A 25-year vs a 35-year mortgage](https://around.ie/compare/25-vs-35-year-mortgage/): Same loan, ten more years: what the longer term saves each month and costs in total.
- [Compound interest vs simple interest](https://around.ie/compare/compound-vs-simple-interest/): The two ways interest can be calculated, how far apart they end up, and which one you are actually being offered.
- [Monthly vs annual compounding](https://around.ie/compare/monthly-vs-annual-compounding/): How much compounding frequency really matters, with the honest answer: less than most people expect.
- [VAT vs sales tax](https://around.ie/compare/vat-vs-sales-tax/): Two ways of taxing consumption: collected along the chain or once at the till — and why the sticker price differs.
- [Inflation vs deflation](https://around.ie/compare/inflation-vs-deflation/): Rising prices against falling ones — why economists fear the second more than the first, explained without panic.
- [Julian vs Gregorian calendar](https://around.ie/compare/julian-vs-gregorian-calendar/): Why the calendar was reformed, what changed, and how ten days went missing when countries switched.
- [Percentage change vs percentage difference](https://around.ie/compare/percentage-change-vs-difference/): One is directional, one is symmetric — which to use, and how the same two numbers give different answers.

## Worked examples (all figures computed deterministically)

- [A €300,000 mortgage at 4%](https://around.ie/examples/300000-mortgage-at-4-percent/): The full anatomy of a typical mortgage: monthly repayment, total interest, and how the balance falls year by year.
- [What a quarter-point rise does to a mortgage](https://around.ie/examples/quarter-point-on-a-mortgage/): The smallest step a central bank usually takes, priced on a €300,000 mortgage: €43.57 a month, worked through.
- [Starting at 25 vs starting at 35](https://around.ie/examples/starting-at-25-vs-35/): Ten years’ head start, same monthly saving: the gap at retirement is bigger than most people guess.
- [The best ways to spend leave days in Argentina in 2026](https://around.ie/examples/leave-plan-argentina-2026/): Where Argentina's 2026 public holidays already lean your way: the year's best bridges and blocks, computed from the calendar.
- [The best ways to spend leave days in Australia in 2026](https://around.ie/examples/leave-plan-australia-2026/): Where Australia's 2026 public holidays already lean your way: the year's best bridges and blocks, computed from the calendar.
- [The best ways to spend leave days in Brazil in 2026](https://around.ie/examples/leave-plan-brazil-2026/): Where Brazil's 2026 public holidays already lean your way: the year's best bridges and blocks, computed from the calendar.
- [The best ways to spend leave days in Canada in 2026](https://around.ie/examples/leave-plan-canada-2026/): Where Canada's 2026 public holidays already lean your way: the year's best bridges and blocks, computed from the calendar.
- [The best ways to spend leave days in France in 2026](https://around.ie/examples/leave-plan-france-2026/): Where France's 2026 public holidays already lean your way: the year's best bridges and blocks, computed from the calendar.
- [The best ways to spend leave days in Germany in 2026](https://around.ie/examples/leave-plan-germany-2026/): Where Germany's 2026 public holidays already lean your way: the year's best bridges and blocks, computed from the calendar.
- [The best ways to spend leave days in Ireland in 2026](https://around.ie/examples/leave-plan-ireland-2026/): Where Ireland's 2026 public holidays already lean your way: the year's best bridges and blocks, computed from the calendar.
- [The best ways to spend leave days in Italy in 2026](https://around.ie/examples/leave-plan-italy-2026/): Where Italy's 2026 public holidays already lean your way: the year's best bridges and blocks, computed from the calendar.
- [The best ways to spend leave days in Mexico in 2026](https://around.ie/examples/leave-plan-mexico-2026/): Where Mexico's 2026 public holidays already lean your way: the year's best bridges and blocks, computed from the calendar.
- [The best ways to spend leave days in Netherlands in 2026](https://around.ie/examples/leave-plan-netherlands-2026/): Where Netherlands's 2026 public holidays already lean your way: the year's best bridges and blocks, computed from the calendar.
- [The best ways to spend leave days in New Zealand in 2026](https://around.ie/examples/leave-plan-new-zealand-2026/): Where New Zealand's 2026 public holidays already lean your way: the year's best bridges and blocks, computed from the calendar.
- [The best ways to spend leave days in Poland in 2026](https://around.ie/examples/leave-plan-poland-2026/): Where Poland's 2026 public holidays already lean your way: the year's best bridges and blocks, computed from the calendar.
- [The best ways to spend leave days in Portugal in 2026](https://around.ie/examples/leave-plan-portugal-2026/): Where Portugal's 2026 public holidays already lean your way: the year's best bridges and blocks, computed from the calendar.
- [The best ways to spend leave days in Spain in 2026](https://around.ie/examples/leave-plan-spain-2026/): Where Spain's 2026 public holidays already lean your way: the year's best bridges and blocks, computed from the calendar.
- [The best ways to spend leave days in United Kingdom in 2026](https://around.ie/examples/leave-plan-united-kingdom-2026/): Where United Kingdom's 2026 public holidays already lean your way: the year's best bridges and blocks, computed from the calendar.
- [The best ways to spend leave days in United States in 2026](https://around.ie/examples/leave-plan-united-states-2026/): Where United States's 2026 public holidays already lean your way: the year's best bridges and blocks, computed from the calendar.
- [Overpaying a mortgage by €100 a month](https://around.ie/examples/overpaying-100-a-month/): What a steady €100 overpayment does to a €300,000 mortgage: the years removed and the interest saved.
- [How many working days are in 2026?](https://around.ie/examples/working-days-in-2026/): The weekday arithmetic of one year, worked through: total days, weekends, and Monday-to-Friday working days.
- [Down 20%, up 25%: why falls need bigger rises](https://around.ie/examples/down-20-up-25/): A worked example of percentage asymmetry: what falls by 20% must rise by 25% just to get back where it started.
- [What €100 buys after 20 years of inflation](https://around.ie/examples/what-100-buys-in-20-years/): The quiet arithmetic of 2% a year: what today’s €100 of shopping costs in 10, 20 and 35 years.
- [€100 a month for 30 years](https://around.ie/examples/100-a-month-for-30-years/): A worked example of steady small saving: what €100 a month becomes over 30 years at different rates.
- [When savings lose money while growing](https://around.ie/examples/negative-real-returns/): A worked example of negative real returns: 2% interest under 5% inflation is a loss wearing a plus sign.
- [The same mortgage over 25, 30 and 35 years](https://around.ie/examples/same-mortgage-three-terms/): One loan, three terms: how the monthly payment and the lifetime interest trade against each other.
- [Why 20% off then 10% off isn’t 30% off](https://around.ie/examples/stacked-discounts/): A worked example of stacked percentages: successive discounts multiply rather than add, and the gap is real money.
- [Born on 29 February: how leap-day birthdays work](https://around.ie/examples/leap-day-birthdays/): A 29 February birthday arrives every four years — how the maths of leap-day ages actually works out.
- [VAT on €100, worked through](https://around.ie/examples/vat-on-100-euro/): What the standard and reduced Irish rates each do to a €100 net price — and how to read the gross that results.
- [A €10,000 lump sum left for 20 years](https://around.ie/examples/10000-lump-sum-for-20-years/): What happens when you invest once and leave it alone — €10,000 over 20 years at different rates.
- [Removing VAT from a price](https://around.ie/examples/removing-vat-from-a-price/): Getting the net out of a VAT-inclusive price: divide, never subtract — worked with real numbers.
- [How fast money doubles at different rates](https://around.ie/examples/how-fast-money-doubles/): Exact doubling times from 1% to 12%, side by side with the Rule of 72 estimate.

## Glossary

- [LTV (loan-to-value)](https://around.ie/glossary/ltv/): The mortgage as a percentage of the property’s value — the number that sets your deposit and often your rate.
- [Central bank](https://around.ie/glossary/central-bank/): The institution behind a currency: it sets policy rates, targets price stability, and banks the banks.
- [APR (annual percentage rate)](https://around.ie/glossary/apr/): The yearly cost of borrowing including standard charges, used to compare loans and credit cards.
- [APRC (annual percentage rate of charge)](https://around.ie/glossary/aprc/): The all-in yearly cost of a mortgage including fees, designed so offers can be compared like-for-like.
- [CPI (consumer price index)](https://around.ie/glossary/cpi/): The basket-of-goods index used to measure inflation — what goes in it and what a CPI figure actually claims.
- [Policy rate](https://around.ie/glossary/policy-rate/): The interest rate a central bank sets on purpose — the lever every other rate in the economy takes its cue from.
- [Basis point](https://around.ie/glossary/basis-point/): One hundredth of a percentage point — the unit finance uses when percentage-point moves are too coarse.
- [Gross and net](https://around.ie/glossary/gross-and-net/): Gross is the amount with everything included; net is what remains after deductions — which is which depends on context.
- [AER (annual equivalent rate)](https://around.ie/glossary/aer/): What a savings rate really pays over a year once compounding frequency is taken into account.
- [Percentage point](https://around.ie/glossary/percentage-point/): The unit for the gap between two percentages — the difference between 4% and 6% is two percentage points, not 2%.
- [Purchasing power](https://around.ie/glossary/purchasing-power/): What money can actually buy — the quantity inflation erodes even while the number in the account grows.
- [Equity (property)](https://around.ie/glossary/equity/): The slice of your home you actually own: its value minus what is still owed on the mortgage.
- [UTC (Coordinated Universal Time)](https://around.ie/glossary/utc/): The world’s reference clock — the time standard every time zone is defined as an offset from.
- [Zero-rated (VAT)](https://around.ie/glossary/zero-rated/): Goods taxed at a VAT rate of nothing — which is not the same as being exempt, and the difference matters to businesses.
- [Deflation](https://around.ie/glossary/deflation/): Prices falling across the economy — rarer than inflation, and more feared by the people who set interest rates.
- [Gregorian calendar](https://around.ie/glossary/gregorian-calendar/): The civil calendar most of the world runs on, introduced in 1582 to stop the seasons drifting through the year.
- [Amortisation](https://around.ie/glossary/amortisation/): Paying a loan down with instalments that cover interest first and principal with the rest, on a fixed schedule.
- [ISO 8601](https://around.ie/glossary/iso-8601/): The international standard for writing dates and times — year first, so dates sort correctly as text.
- [Real return](https://around.ie/glossary/real-return/): An investment’s return after inflation — the growth in what your money can actually buy.
- [Compounding frequency](https://around.ie/glossary/compounding-frequency/): How often earned interest is added to the balance — yearly, monthly or daily — so it can start earning interest itself.
- [Future value](https://around.ie/glossary/future-value/): What an amount of money will be worth at a set date in the future, given a rate of growth.
- [Principal](https://around.ie/glossary/principal/): The original amount of money saved, invested or borrowed, before any interest is added.