Unit Converter
Convert between common units of length, weight, volume, temperature, area, and speed all in one place. Supports both US customary and metric units with instant results.
Formulas, assumptions, and rounding are documented in our calculator methodology.
1 Meters (m) = 3.28084 Feet (ft)
How to Use the Unit Converter
Select a measurement category (length, weight, volume, temperature, area, or speed), enter a value in any field, and all other fields update instantly. Switch between categories using the selector at the top. The converter works in both directions — enter metric to get US customary, or vice versa.
Most Common Unit Conversions
Length: 1 inch = 2.54 cm | 1 foot = 0.3048 m | 1 mile = 1.60934 km. Weight: 1 pound = 453.592 g | 1 kg = 2.20462 lbs. Volume: 1 US gallon = 3.78541 L | 1 cup = 236.6 ml. Temperature: °C = (°F − 32) × 5/9 | 0°C = 32°F. Area: 1 acre = 43,560 sq ft | 1 sq meter = 10.764 sq ft. Speed: 1 mph = 1.60934 km/h.
Precision and Rounding in Unit Conversion
Exact conversion factors (like 1 inch = 2.54 cm exactly, by international definition) produce exact results. Others are rounded approximations. In cooking, rounding to the nearest milliliter or gram is fine. In engineering and science, use the full precision shown. When in doubt, this calculator shows at least 4 decimal places so you can round to the precision your task requires.
Why Use a Unit Converter?
Unit conversion errors cause real problems — from recipe failures to construction overruns to medication errors. A cup is not the same in the US (237 ml) and Australia (250 ml). A US gallon (3.79 L) is not a UK gallon (4.55 L). Using a reliable converter eliminates guesswork and prevents costly mistakes in any task where precision matters.
Frequently Asked Questions
- This unit converter supports length (inches, feet, yards, miles, mm, cm, m, km), weight (oz, lbs, grams, kg, metric tons), volume (tsp, tbsp, cups, pints, quarts, gallons, ml, liters), temperature (°F, °C, K), area (sq ft, sq yd, sq m, acres, hectares), and speed (mph, km/h, m/s, knots).
- All conversions use internationally accepted conversion factors. Results are accurate to at least 6 significant figures. For most everyday uses (cooking, construction, travel), this level of precision exceeds what is practically needed.
- The metric system (SI) uses units like meters, kilograms, and liters, with a base-10 structure making conversions between sub-units simple (1 km = 1,000 m). The US customary system uses inches, pounds, and gallons with irregular conversion factors (1 mile = 5,280 feet). Most of the world uses metric; the US, Myanmar, and Liberia primarily use customary units.
- Yes, completely free with no account or sign-up required.
- Yes. Enter a value and select a unit type to see conversions across all units in that category simultaneously. Changing any field recalculates all other fields instantly.