Universal Unit Converter
InstantA fast, two-way unit converter for length, weight, and temperature. Switch between metric and imperial units with a quick-swap button and adjustable precision rounding.
Universal Unit Converter
1 mm = 0.001 m
How the math works
Linear: value_base = value × factor_from; result = value_base / factor_to
Temperature: °F = °C × 9/5 + 32; K = °C + 273.15Length and weight conversions route every value through a base unit (metres and grams respectively) using exact internationally defined factors. Temperature uses explicit formulas because its scales have different zero points.
Common conversion factors
- 1 inch = 2.54 cm (exact)
- 1 foot = 0.3048 m (exact)
- 1 mile = 1609.344 m
- 1 pound = 453.59237 g
- 1 ounce = 28.349523125 g
- 0 °C = 32 °F = 273.15 K
Frequently asked questions
Which units can I convert?+
Length (metres, kilometres, feet, inches, miles), weight (kilograms, grams, pounds, ounces), and temperature (Celsius, Fahrenheit, Kelvin).
How accurate are the conversions?+
Conversions use exact internationally defined factors (for example, 1 inch = 0.0254 m exactly). You can control display precision with the rounding selector.
How do I convert Celsius to Fahrenheit?+
Multiply the Celsius value by 9/5 and add 32. For example, 20 °C × 9/5 + 32 = 68 °F. The converter does this automatically as you type.