Unit Converter
Convert between metric, imperial and US units of length, weight, temperature, volume, speed, area and digital storage, using exact conversion factors.
1 metre (m) = 3.280839895 foot (ft)
Results are rounded to 10 significant digits.
About the Unit Converter
Pick a category, choose the units to convert from and to, and type a value; the result appears as you type. Seven categories cover the everyday cases: centimetres and inches for a screen or a parcel, kilograms and pounds for luggage, Celsius and Fahrenheit for weather or an oven, litres and gallons for fuel, km/h and mph, square feet and square metres for a flat listing, and gigabytes for storage.
The conversion factors are the exact legal definitions rather than rounded approximations: 1 inch is 2.54 cm, 1 foot is 0.3048 m, 1 mile is 1,609.344 m, 1 pound is 0.45359237 kg, 1 US gallon is 3.785411784 litres, 1 UK gallon is 4.54609 litres and 1 acre is 4,046.8564224 m². Temperature uses formulas instead of a ratio: °F = °C × 9/5 + 32 and K = °C + 273.15, so 100 °C is 212 °F and −40 is the same on both scales. Results are rounded to 10 significant digits, which hides the tiny floating-point errors computers produce without losing useful precision.
Where a unit name is ambiguous, the list spells out which one you are using. The US gallon and the UK (imperial) gallon differ by about 20%, and a "ton" can mean a US short ton (907.18474 kg), a UK long ton (1,016.0469088 kg) or a metric tonne (1,000 kg). For storage, kilobyte, megabyte, gigabyte and terabyte are decimal (1 kB = 1,000 bytes), as drive makers use them, while kibibyte and its larger relatives are binary (1 KiB = 1,024 bytes). That difference is why a 1 TB drive shows up as about 931 GiB. For time and money, see the Timezone Converter and the Currency Converter.
How to use the Unit Converter
- 1
Choose a category
Click Length, Weight, Temperature, Volume, Speed, Area or Digital Storage. Switching category resets the value to 1.
- 2
Pick the units
Select the unit you have in the From list and the unit you want in the To list.
- 3
Enter the value
Type a number in the From box. The result and a full sentence such as "1 inch (in) = 2.54 centimetre (cm)" appear immediately.
- 4
Swap if needed
The arrow button between the boxes swaps the two units and moves the result into the From box.
What it can do
55 units in 7 categories
Metric, imperial and US customary units, plus nautical miles, knots and both kinds of storage unit.
Exact definitions
Factors such as 0.45359237 kg per pound and 0.09290304 m² per square foot are used in full.
Clearly named variants
US and UK gallons, short and long tons, and decimal and binary storage units are listed separately.
Correct temperature maths
Celsius, Fahrenheit and Kelvin conversions use offset formulas, so negative and freezing-point values come out right.
Limitations
- There are no conversions between volume and weight, such as cups of flour to grams, because those depend on the density of the ingredient.
- Regional land units such as bigha, guntha or cent are not included, partly because some of them, like the bigha, vary between states.
- Only the seven listed categories are covered; pressure, energy, power, time and fuel economy are not.
- Results are rounded to 10 significant digits.
Privacy
Conversions are calculated by JavaScript in your browser; nothing you enter is sent to FlexyPdf's servers.
Frequently asked questions
How many centimetres are in an inch?
Exactly 2.54. The inch has been defined as 25.4 mm since the international yard and pound agreement of 1959, so 12 inches (one foot) is 30.48 cm.
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 and add 32. A body temperature of 37 °C is 37 × 1.8 + 32 = 98.6 °F. To go back, subtract 32 and multiply by 5/9.
How many square feet are in a square metre?
About 10.764. One square foot is exactly 0.09290304 m², so a 1,000 sq ft flat is roughly 92.9 m². Choose Area, then square foot and square metre.
Why does my 1 TB drive show only about 931 GB?
The drive maker counts 1 TB as 1,000,000,000,000 bytes, while some operating systems divide by 1,024 three times and label the result GB. In this converter 1 TB equals 931.32 GiB.
Which gallon does the converter use?
Both are available and labelled: the US gallon (3.785411784 L) and the UK imperial gallon (4.54609 L). Quarts, pints, cups and spoons in the list are US measures.
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