EN中文

Convert · Common measurements

Unit Converter

Convert length, mass, temperature, area, volume, and speed units with clearly labeled US, imperial, and metric definitions.

Six categories

Convert a measurement

Runs in your browser
Common conversions
Converted value3.280839895 ft

1 m equals 3.280839895 ft

Conversions happen locally. US and imperial volume units are labeled separately.

Supported measurement categories

This converter covers common units of length, mass, temperature, area, volume, and speed. Choose a category first, then select the source and target units. Results update immediately and use up to ten significant digits for practical precision.

Conversion method

Most units use a defined factor to convert the input to a category base unit and then into the target unit. For example, one international mile is exactly 1,609.344 meters, and one international pound is exactly 0.45359237 kilograms.

Temperature needs both scaling and an offset:

  • Fahrenheit to Celsius: °C = (°F − 32) × 5 ÷ 9
  • Celsius to Fahrenheit: °F = °C × 9 ÷ 5 + 32
  • Celsius to kelvin: K = °C + 273.15

US and imperial volume units

Units with similar names are not always equal. One US gallon is exactly 3.785411784 liters, while one imperial gallon is exactly 4.54609 liters. The tool labels these separately. “Fluid ounce” and “cup” in this initial converter refer specifically to US customary definitions.

Precision and rounding

Calculations use JavaScript double-precision numbers without intermediate display rounding. Ordinary results show up to ten significant digits; very large or very small values may use scientific notation. A displayed decimal is an approximation when the exact conversion has infinitely repeating digits.

Frequently asked questions

Is mass the same as weight?

Kilograms and pounds are technically units of mass. Everyday language often calls the measurement “weight,” but force depends on gravity and is measured separately, such as in newtons.

Why does an area conversion use a squared factor?

Area has two dimensions. Since one foot equals 0.3048 meters, one square foot equals 0.3048², or exactly 0.09290304 square meters.

Can I use the result for engineering work?

The factors are suitable for general conversions, but engineering, laboratory, surveying, and regulatory work may require controlled significant figures, calibrated measurements, uncertainty analysis, or a prescribed standard.

Use the Percentage Calculator for ratios and percentage changes, or the Salary Calculator for gross-pay period conversions.