Conversion Calculator
Convert between any two units across 15 measurement categories.
All calculations happen locally in your browser — nothing is uploaded, stored or tracked.
Pick a category
One of fifteen measurement families.
Select the units
From and to.
Type the value
The conversion updates live.
What Is a Conversion Calculator?
This is the broad version of the unit converter: fifteen measurement categories spanning everyday and technical units — from fuel economy and pressure to power and angle. Every conversion uses fixed, well-established factors.
Temperature conversions use the standard offset formulas; all other categories convert by dividing the unit factors. Results are shown with up to six decimal places, and the display uses sensible precision automatically.
Supported Categories
- Length, weight, temperature, area, volume, speed and time
- Data storage and data transfer rates
- Energy, power, pressure and fuel economy
- Angle (degrees, radians, gradians) and frequency
How It Works
Each unit carries a factor relative to a base unit. Converting is a single division. Because the factors are constants, results are exact for the inputs you provide.
Your data never leaves your device.
Every calculation on this site runs in your browser using vanilla JavaScript. Nothing is uploaded, stored or tracked.
- 100% local, client-side calculations
- No data stored on any server
- No tracking, no analytics, no ads scripts
- Works offline once loaded
Frequently Asked Questions
How many unit categories are supported?
Fifteen: length, weight, temperature, area, volume, speed, time, data storage, data transfer, energy, power, pressure, fuel economy, angle and frequency.
Is the conversion exact?
Yes — the conversion factors are fixed constants (e.g. 1 inch = 2.54 cm exactly), so results are exact within the display precision.
How do I convert miles per gallon to litres per 100 km?
Use the fuel economy category: L/100km = 235.215 ÷ MPG. The calculator handles the conversion factor.
What units are in the pressure category?
Pascal, bar, psi, atmosphere, mmHg and more, all relative to the pascal.
Does it work offline?
Yes — no network calls are made; all factors ship with the page.