Free · private · worldwide
Money calculators that show their working
Free, private and worldwide. Taxes for the US, UK, Canada, Australia and Germany — more countries as we verify them.
Where are you?
United States: US paycheck calculator is live.
United Kingdom: UK take-home pay calculator is live.
Canada: Canada take-home pay calculator is live.
Australia: Australian pay calculator is live.
Germany: Germany net salary calculator is live.
Pick your country to set your currency. Universal calculators work everywhere; for anywhere else, enter your own tax bands in the tax bracket calculator.
Worked example · compound interest
$10,000.00 at 5% a year, compounded yearly, for 10 years
- Year 1$10,500.00
- Year 2$11,025.00
- Year 5$12,762.82
- Year 10$16,288.95
10,000 × 1.0510
Final balance$16,288.95
Try it with your numbers- Rules checked against official sources
- Calculated in your browser
- Every rate dated and cited
What do you want to work out?
Every calculator updates as you type, shows each step of the maths, and exports to CSV. Pick a currency once and it’s remembered on this device.
Pay & tax
Turn pay into hourly, monthly or yearly figures and work through income tax bands.
Save & grow
Project savings with compound interest and find out what a goal really takes.
Borrow & repay
Repayments, amortization schedules and what overpaying changes.
Everyday maths
Percentages, discounts, VAT, GST and sales tax, done properly.
Plan
What money was worth then and now, and across borders.
Numbers you can check, not just numbers
Most finance calculators give you a total and ask you to trust it. MoneyOtter shows the working instead. Open Show working under any result and you’ll see each step: the rate converted to a rate per period, the formula used, the inputs that went in and the rounding applied. If a figure looks surprising, you can follow it back to where it came from.
The same calculators work wherever you live. Choose your currency and the amounts format the way you write them. Interest conventions follow what lenders and banks in different places actually quote: an AER or APY already includes compounding, a nominal rate doesn’t, and fixed-rate Canadian mortgages compound twice a year. You choose the convention and the result tells you which one it used.
Everything happens in your browser. The amounts you type are not sent to our servers, there’s nothing to sign up for, and nothing is saved unless you choose to keep it. Share links carry your figures in the part of the address after the #, which browsers don’t send to websites.
We calculate and explain; we never advise. You won’t find product recommendations or “you should” here. Where a decision depends on things we can’t see, such as early repayment charges, your tax position or how much cash you want to keep aside, the calculator says so.
Show working
Every result lists its steps, formula and rounding, generated by the same code that produced the figure.
Any currency
ISO currency rules, so yen have no decimals and dinars have three. Amounts up to a trillion stay exact.
Free exports
Copy a summary, download the full schedule as CSV, print a clean page or share a link. No paywall.
Private by design
No accounts and no uploads. Reference data is the same static file for every visitor.
Deep, verified country rules — one country at a time
Take-home pay depends on detailed national rules that change every year. Rather than cover every country thinly, MoneyOtter publishes a country only when its calculator passes a strict bar: rules taken from the tax authority’s own publications with every figure cited, at least thirty test cases including official worked examples, and an independent re-implementation that must agree with ours on thousands of random cases.
Live now: US paycheck calculator, UK take-home pay calculator, Canada take-home pay calculator, Australian pay calculator, Germany net salary calculator. The take-home pay hub compares the same salary across them. For anywhere else, the income tax bracket calculator lets you enter your own bands.
You can see where each country stands, and which ones are planned next, on the countries page. How every calculator works, including rounding and test cases, is on the methodology page.
Country status
- United StatesLive
- United KingdomLive
- CanadaLive
- AustraliaLive
- GermanyLive
US states: California, New York, Pennsylvania, Illinois, Ohio, Georgia, North Carolina, Michigan.
Planned next: Ireland, New Zealand, India, South Africa, Singapore, Netherlands.
What changed, and when
- Calculators
Inflation calculator: “Annual average” now uses the publisher’s own published annual averages (US BLS CPI-U, including the 2025 average of 321.943, which BLS calculated from the 11 months it published because October 2025 was never collected). Unpublished months and years still in progress show a clear message; nothing is interpolated.
- Calculators
First release of the universal calculators: compound interest, savings goal, loan, mortgage (with overpayments and a Canadian semi-annual compounding preset), inflation, currency converter, VAT/GST/sales tax, percentage, salary to hourly and the custom income tax bracket calculator. Each is tested against the worked examples in our specification.
- Data
Currency conversion uses European Central Bank euro reference rates published as static files on this site. Inflation figures use official consumer price indexes from national statistics offices, each shown with its publisher, licence and latest observation.
Understand the maths
- APR, AER, APY and nominal rates: what interest rates really meanWhy two “5%” rates can cost or pay different amounts, and how to convert between them.
- Debt avalanche vs debt snowball: how each method works and what it costsHighest rate first or smallest balance first, worked through month by month.
- Overpay the mortgage or save the money? How to compare the twoInterest saved versus interest earned, after tax, with the catches that matter.
- How inflation is measured: consumer price indexes explainedThe basket, the weights, the index and the headline rate, country by country.
- Gross vs net pay: what comes out of your salaryIncome tax, social contributions and pre-tax savings, country by country, with real numbers.
- Marginal vs average tax rate: what a tax bracket really meansWhy moving up a bracket only taxes the extra, and where the real marginal rate jumps.
- Your US paycheck explained: federal tax, FICA and state withholdingEvery line on a US pay stub, and why withholding and the tax you owe can differ.
- Converting a salary to an hourly rate (and back again)Hours, paid leave, overtime and tax: what makes two pay offers comparable.
- How VAT and sales tax work: adding and removing tax correctlyThe formulas for adding and removing VAT, GST or sales tax, and the common mistakes.
- Percentages that trip people up: change, points, margin and markupPercentage change, percentage points, reversing a discount, and margin versus markup.
About MoneyOtter
MoneyOtter is run by Infinity Square Labs Ltd, a small UK company that builds free, privacy-first web tools. Read more about us.
Are MoneyOtter’s calculators really free?
Yes. Every calculator is free to use with no sign-up and no paywall on any result, export or schedule. The site is funded by a small number of clearly labelled ads that never appear inside a calculator.
Does MoneyOtter work outside the US?
Yes. The universal calculators work in any currency, with local number formats and conventions such as AER, APR as an effective rate, and Canadian semi-annual mortgage compounding. Country take-home pay calculators are published one country at a time, only after they pass official test cases and an independent cross-check.
Is the money I type sent anywhere?
No. Calculations run in your browser. The amounts you type are not sent to our servers or stored. The only files the calculators download are the same reference data files for every visitor, such as exchange rates and price indexes.
Is this financial advice?
No. MoneyOtter calculates and explains; it never advises. Results are estimates for general information. Each one shows its working and assumptions so you can check it, and the disclaimer explains the limits.