About Our Conversion Calculators
This category brings together converters for common measurement questions. The tools are designed to turn a value in one unit into an equivalent value in another unit while showing the selected units, conversion relationship and rounding behavior.
Convert length, weight, temperature, volume and cooking measurements.
Work with area, speed and pressure units used in daily and technical settings.
Convert energy, power, data storage and fuel-economy measurements.
How to use these calculators
Select the converter that matches your measurement, enter a value, choose the source unit and select the target unit. Review the converted result together with the displayed precision and conversion relationship.
Why conversion results can differ
Converted values can vary slightly because of rounding, display precision, different unit definitions or selected conventions. Check each converter’s explanation for internal precision and displayed rounding.
- Mass and weight are distinct physical quantities, though everyday converters often group their common units.
- U.S. customary and imperial volume units with similar names may have different sizes.
- Digital storage may use decimal or binary multiples depending on the selected convention.
- Fuel-economy conversions require reciprocal relationships, not only a fixed multiplier.
Accuracy note: Check the selected source and target units and use appropriate precision. Verify critical engineering, medical, laboratory or trade measurements with an authoritative standard.
Choose the right unit conversion calculator
For a distance, use the Length Converter: one inch equals exactly 2.54 centimeters, so 12 inches equals 30.48 centimeters. For a temperature, use the Temperature Converter: (68 − 32) × 5 ÷ 9 gives 20 °C. Temperature conversions may require an offset as well as a multiplier.
Use the Volume Converter for liquid measures, and choose U.S. customary or imperial units explicitly. A U.S. gallon and an imperial gallon are not interchangeable. For recipes, the Cooking Measurement Converter converts within volume or mass; converting cups to grams also needs the ingredient density and cannot be inferred from the unit names alone.
For digital files, use the Data Storage Converter and distinguish decimal GB from binary GiB. For mileage comparisons, use the Fuel Economy Converter; miles per gallon and liters per 100 kilometers describe reciprocal measures.
Measurement references
Defined relationships and unit conventions can be checked in NIST Special Publication 811, Guide for the Use of the International System of Units. Each converter explains its supported units and rounding; a conversion does not improve the accuracy of the original measurement.