Calculators that show their working
Most calculators hand you a number and hope you do not ask where it came from. These name the formula, name the authority behind any rate they use, date it, and let you change it. Pick your market and the rules, currency and units follow.
Pick your country
Rates, statutory rules and units differ by market, so each country has its own set.
Why a country selector rather than one global site
A VAT calculator that does not know which country you are in is not a VAT calculator, it is a percentage calculator with a misleading name. Stamp duty bands, statutory leave, overtime multipliers, admission scores and building-fabric targets are all national. So are the units people measure in and the currency they think in.
Each market on this site is built against its own published sources, so a figure on the Irish section comes from Revenue and a figure on the Singapore section comes from IRAS. Where a calculation genuinely is universal — the maths of a matrix, the heat load of a room, the gestation of a ewe — the same engine runs everywhere, and only the worked example and the units change.
What showing the working actually means
Three things, on every page. The method is named, so you know whether a concrete estimate uses nominal volume proportions or a designed mix. The source is named and dated, so you know a tax band came from the revenue authority and when it was last checked. And where the number is one that changes, there is a field to type in your own.
That last part is the one most calculators skip, and it is the one that stops a tool being quietly wrong two years after it was built. A rate you can override is a rate you can trust, because you can check it.
Fast, private, and offline once loaded
Every calculation happens in your browser. Nothing you type is transmitted, logged or stored — not the salary you are checking, not the property price, not the health measurements. There is no account, no email wall in front of a result, and no advertising.
The practical effect is speed. Pages carry no third-party scripts and no libraries, so a tool is usable almost immediately even on a slow mobile connection, and it keeps working if the connection drops after the page has loaded.
Where we are deliberately incomplete
Some popular calculators are not built and will not be. Anything that needs a live lookup against a licensed database cannot run in a browser, so vehicle valuation by registration number and duty by commodity code are absent rather than approximated.
Medication dosing is not built, because the consequence of an error is not a wasted bag of cement. Personal-injury compensation estimates are not built, because payouts are decided case by case and a calculator implies a precision that does not exist. And a small number of tools are held back pending a deliberate editorial decision rather than shipped because the search volume looked attractive.
Questions people ask about this
Do I need an account to use these calculators?
No. There is no sign-up, no email capture and no paywall anywhere on the site. Every calculator is fully usable the moment the page loads, and the result is never held back behind a form.
Is anything I type stored or sent anywhere?
No. The calculations run entirely in your browser using a small script on the page. Salaries, property prices, health measurements and everything else stay on your device, and are gone when you close the tab.
Which country should I use if I live in one and work in another?
Use the section for the country whose rules apply to the question. Tax and statutory entitlements follow where you are employed or where the property sits, not where you live. For universal calculations like maths, physics or materials, any country's version gives the same answer — only the units and worked examples differ.
How do I report a calculator that gives the wrong answer?
Email hello@calculatorplus.website with the tool, the inputs you used and the figure you expected. Corrections to a formula or a stale rate are treated as urgent, because a confidently wrong calculator is worse than no calculator.