Online calculators

Enter three values and leave one blank. Solve direct or inverse proportions with clear steps, exact fractions and everyday examples.

Add, subtract, multiply or divide fractions and mixed numbers. See reduced fractions, mixed results and decimal approximations.

Calculate simple or weighted averages, inspect imported numbers and work out a required next grade on your chosen scale.

Find a percentage, a share or the change between two values.

Explore how a starting balance and regular savings could grow.

Record who paid and who shares each expense. Calculate balances in exact cents and export a clear settlement list.

Calculate gross margin and markup separately, or find a selling price for your target margin. See the basis behind each percentage.

Find the sales quantity and revenue needed to cover fixed and variable costs. Compare a sales scenario with the break-even point.

Compare quantity, unit price, discount, shipping and extra costs on the same basis. Keep delivery times alongside the calculated totals.

Count or add working days using your own weekdays and manual excluded dates. Choose date boundaries and inspect every counted or skipped date.

Calculate daily and weekly work hours, breaks and target differences. Check overnight shifts and export a time sheet.

Count calendar days between two dates, without timezone surprises.

Run several named countdowns for cooking, breaks or everyday tasks. Pause and reset independently, with optional sound.

Convert length, mass, temperature, volume, area and speed.

Plan straight cuts for boards or sticks with kerf, rotation and grain constraints.