Small calculators. Exact formulas.
30 calculators for everyday jobs. Every page shows how the result is calculated. No sign-up, no cookies.
Home and DIY
Paint, tiles, flooring, concrete and stairs: how much to buy, with waste included.
Garden and water
Soil, gravel, plants, pools and rainwater.
Kitchen
Scale recipes, convert cups and oven settings, and get ratios right.
Car and travel
Fuel cost and fuel economy conversions.
Energy at home
What appliances and lamps cost to run.
Everyday numbers
Prices, percentages, hours and dates.
Building software or an AI agent? The same exact maths is available as an API: the calculator tool.