Converters
Converters translate measurements between the metric and imperial worlds — and between the everyday units inside each. FreeToolsKit's unit converter covers eight categories with exact international conversion factors, and prints the formula next to every result so the maths is never a mystery.
Last updated: October 20, 2026
Why use these converters?
- Exact factors — conversions use international definitions, like 1 inch = exactly 25.4 mm.
- Temperature done properly — offset formulas (°F = °C × 9/5 + 32), not naive multiplication.
- One-click swap — reverse any conversion without re-selecting units.
Frequently asked questions
How accurate are the conversions?
They use the exact international definitions of each unit. Displayed results are rounded for readability, keeping more precision than everyday use needs.
Which categories are covered?
Length, Weight, Temperature, Volume, Speed, Data, Time and Area — the units that come up in cooking, travel, health, computing and home projects.
Why can't I convert kilograms to litres?
Mass and volume measure different things; converting between them requires a substance's density. The converter sticks to conversions that are always true.