Unit Converter
Convert measurements across 13 categories. Choose your units and see the result instantly.
How to use this tool
Pick a category
Length, weight, temperature, area, volume, speed or time.
Enter a value
Type the number and choose the from and to units — or tap swap.
Get the answer
The result updates live as you type, with the exact conversion rate.
Frequently asked questions
How precise are the conversions?
We use exact international definitions (e.g. 1 inch = 2.54 cm exactly, 1 lb = 0.45359237 kg exactly). Results show up to 10 significant digits with trailing zeros trimmed.
Does temperature conversion handle negatives?
Yes — enter any value, including below zero. Celsius, Fahrenheit and Kelvin all convert correctly in both directions.
Is my input sent anywhere?
No. Every calculation runs in your browser with JavaScript. Nothing you type ever leaves your device.
Why do some categories have fewer units?
We list the units people actually use, not hundreds of obscure ones. If a unit you need is missing, the common equivalents are all here.
Can I convert very large or small numbers?
Yes — the converter handles scientific-scale values (like nanometers to light-years) within normal floating-point precision.