Free · No sign-up · Runs in your browser
Finance calculators
that show
their work.
Most calculators hand you a number and hide the arithmetic. Every tool here shows the formula, states its assumptions, and gives you the full schedule underneath so you can check the answer instead of trusting it.
- Calculators
- 15
- Categories
- 6
- Sign-up required
- None
Browse by need
Grouped by the question
you are actually asking.
15 calculators published so far. A category appears here once it holds a tool whose maths is tested and whose sources are cited, not before.
- Mortgage & Home Work out payments, affordability, amortisation and the cost of paying early. 2 tools
- Loans & Debt Payments, interest, amortisation and payoff strategies for any fixed-rate loan. 4 tools
- Saving & Investing Compound growth, contributions, returns, inflation and goal planning. 4 tools
- Salary & Pay Convert pay periods, compute overtime, raises and take-home pay. 1 tool
- Business Margins, markup, break-even, ROI and business financing. 2 tools
- Everyday Money Percentages, discounts, budgets, savings goals, net worth and inflation. 2 tools
How a calculator page works
An answer you can check, in three parts.
-
You get the number
Type your figures and the result updates as you go. Nothing is submitted and there is no calculate button to hunt for.
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Then the working
The formula it evaluated, a worked example with real values, and the full schedule row by row, not a summary of it.
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And what it assumes
Every tool states what it does not model, and cites the law or convention behind any rule it applies, with the date checked.
Pick a question
Start with the one you came for.
Every tool is free, needs no account, and runs entirely in this browser tab.