Unit Converter - Free Online Metric & Imperial Tool

How to Use the Unit Converter

Choose a category from the dropdown (Length, Weight, Area, Volume, Speed, Data, Temperature, Pressure, Energy, or Time).
Type your value into the number field - the result updates instantly.
Pick your source unit on the left and target unit on the right.
Click Copy to take the result to your next step.

This Unit Converter covers ten measurement categories - length, weight, area, volume, speed, digital storage, temperature, pressure, energy, and time - in one fast browser-side tool. Everything runs locally: no upload, no server, no waiting. Temperature conversions use exact formulas (°C ↔ °F ↔ K ↔ Rankine), not approximations. Pressure and energy include scientific SI units alongside everyday ones.

What's Covered

Each category includes both metric and imperial units plus any common variants you might encounter in practice:

Extensive support for length, weight, area, and volume units
Dedicated modes for temperature, speed, and pressure
Metric and imperial systems with common cooking equivalents
Two-way conversion with an instant unit swap feature
Live updates as you adjust values for quick reference

Frequently Asked Questions

How precise are the temperature conversions?

Celsius/Fahrenheit/Kelvin use the exact linear formulas (°F = °C × 9/5 + 32; K = °C + 273.15). Results are shown to a sensible number of decimals; the underlying calculation uses full JavaScript double precision.

Are imperial gallons different from US gallons?

Yes - 1 imperial gallon ≈ 4.546 L, 1 US gallon ≈ 3.785 L. Both are listed separately so you don’t have to remember which is which.

What about cooking units like cups or tablespoons?

US customary cups (236.588 mL), tablespoons, and teaspoons are included alongside metric mL/L. Be aware US cups, UK cups, and metric cups all differ slightly.

Is anything uploaded for conversion?

No - each conversion is a single multiplication or formula evaluated in your browser.

Whether you are building a furniture project or solving a physics problem, this free online unit converter provides the accuracy you need.

Unit Converter online

Convert length, weight, area, volume, speed and more - metric and imperial