Numbers worked out, not guessed at.

About these tools

Twenty-seven calculators for the sums that come up often enough to be annoying but not often enough to memorise. Money is the biggest group — mortgage and loan repayments, compound interest, savings goals, salary conversions, discounts, tips and VAT. Then the everyday ones: dates and ages, unit and currency-style conversions, fuel costs, bill splitting, and paint or flooring quantities.

Each one updates as you type and shows the formula it used, so you can check the answer rather than just trust it. Nothing needs an account and nothing you enter leaves your device.

Nothing here needs an account, and nothing you put into any of them is uploaded or stored. Every tool is a single page that does one job, so you can bookmark the one you use and skip this page entirely next time.

How to get a useful answer

Every calculator here does arithmetic on the figures you enter, which means the quality of the answer depends entirely on the quality of the inputs. Two habits make the difference. First, use the real numbers rather than the advertised ones — an interest rate quoted as a headline figure is often not the rate you would actually pay once fees are included, and a salary figure is not what arrives in your account. Second, run the calculation more than once with different assumptions.

That second point matters more than most people expect. A retirement projection at 7% annual return and the same projection at 4% produce wildly different figures over thirty years, and neither is a prediction. Seeing the range is the useful output; treating a single run as an answer is how people end up surprised. The same applies to a mortgage at a rate that will reset, or a business projection that assumes steady growth.

What these calculators cannot know

Three limits apply across the financial tools here. Rates and returns are treated as fixed for the whole period, which real ones never are. Tax and lending rules vary by country and are not built into any of them, so nothing here is adjusted for income tax, capital gains, stamp duty, lending caps or affordability tests where you live. And currency selection is a label, not a conversion — changing the symbol relabels the output and applies no exchange rate.

Taken together, that means the results are arithmetic, not advice. They are useful for comparing options against each other, for sanity-checking a figure someone has quoted you, and for understanding how sensitive an outcome is to one assumption. They are not an offer, a quote, an approval or a recommendation, and anything with real money attached to it deserves a conversation with someone qualified and regulated where you live.

Nothing you enter is sent anywhere

Every calculation runs in your browser. Salary figures, debt balances, savings targets and loan details are processed on your own device and are never transmitted, logged or stored on a server. Closing the tab removes them.

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