Length, weight, temperature, volume, speed — any unit, any direction, zero friction.
Select a category at the top (length, weight, temperature, etc.), then choose your "from" and "to" units from the dropdowns. Type a value in the left field and the converted result appears instantly on the right. Hit the swap button to reverse the direction.
The metric system (meters, kilograms, liters) is used by most of the world, while the imperial system (feet, pounds, gallons) is primarily used in the United States. This converter handles both systems and all major derived units within each category.
Temperature conversions use different formulas than simple multiplication. Celsius to Fahrenheit: multiply by 9/5, then add 32. Celsius to Kelvin: add 273.15. The calculator handles all of these formulas automatically.
// How accurate are the conversions?
All conversions use exact or high-precision factor values based on international standards (SI and NIST definitions). Results are displayed to 6 significant figures for maximum practical accuracy.
// Does it work offline?
Yes. Once the page has loaded, all conversions happen locally in your browser. No internet connection is needed to calculate results.
// What units are included?
Length (mm to miles), Weight (mg to tons), Temperature (C/F/K), Volume (ml to gallons), Speed (km/h to knots), and Area (cm² to acres). More categories are added regularly.
// Why is the formula shown?
Showing the formula helps you verify results and understand the math behind the conversion — useful for students, engineers, and anyone who wants to double-check manually.