Online Calculators with worked examples and cited sources
Search calculators or browse by hub. Every tool answers a specific question, shows the formula behind its result, and cites dated public data — so you see exactly how each number is reached. Missing a calculator? Found an error? Tell us using the form below — fixes usually ship within a week.
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Finance
Calculators for borrowing, property, vehicles, investing, retirement, taxes and income decisions.
Wellbeing
Health, nutrition and women’s health calculators designed for practical personal planning.
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Math
Mathematical, statistical, geometric and measurement calculators with transparent methods.
Mathematical Calculators
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Everyday, housing, construction, home-improvement, technology and internet tools.
Everyday Life Tools
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