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.
Browse by category
Finance
Calculators for borrowing, property, vehicles, investing, retirement, taxes and income decisions.
Retirement Calculators
More Calculators
Wellbeing
Health, nutrition and women’s health calculators designed for practical personal planning.
Health and Nutrition Calculators
Math
Mathematical, statistical, geometric and measurement calculators with transparent methods.
Mathematical Calculators
Geometry Calculators
More
Everyday, housing, construction, home-improvement, technology and internet tools.
Suggest an improvement
Found a calculation issue, outdated source, unclear assumption, or missing edge case? Send a short note so we can review it.