Unit Converter
Fourteen Kinds Of Unit In One Place

What A Unit Converter Does For You

You meet units everywhere. A recipe uses cups, a map uses miles, and a spec sheet uses millimeters. So you often need to move a number from one unit to another.

This unit converter does that in one box. First, pick a kind of unit, such as length or weight. Then type a number, and pick the unit you have and the unit you want. The answer appears as you type.

Also, it shows the same value in every unit of that kind. So you can scan one table instead of making ten conversions, and rounding to the right decimal place is the only decision left to you.

Everything runs in your browser. So your numbers never leave your device. That is quick, and it keeps your data private.

How To Use The Unit Converter

First, choose what you want to convert. The list has fourteen kinds, from length and mass to data storage and fuel economy. Also, each kind has its own set of units.

Then type your value. First, you can use a decimal point or a decimal comma. Then you can also type a large number with an exponent, such as 2.5e6.

Next, pick the units. The result shows the number, the unit symbol and the answer. Then a line below it shows what one unit equals, so you can check the rate.

For more detail, see: Wikipedia article on SI units.

See Every Unit At Once

The table under the result lists every unit of the kind you picked. Also, each row shows the unit name, its symbol and the value. Then click a row to make it the target unit.

So this helps when you do not know which unit you need. For example, a length of one kilometer reads as 1000 meters, 0.621371 miles and 3280.84 feet in one glance.

Length, Weight And Volume

First, these three kinds cover most daily jobs. A mile is 1.609344 kilometers, an inch is exactly 2.54 centimeters, and a pound is 0.45359237 kilograms. The tool uses these exact definitions.

Volume has a trap. The US gallon is 3.785 liters, but the UK gallon is 4.546 liters. So the list keeps both, and each one has its own name.

Temperature Needs A Formula

Most units scale by one factor. But temperature does not, because the scales start at different points. Water freezes at 0 on the Celsius scale and at 32 on Fahrenheit.

So the tool uses the real formulas. Fahrenheit equals Celsius times nine fifths, plus 32. Kelvin equals Celsius plus 273.15. Rankine equals Kelvin times nine fifths.

Speed, Time And Data

First, speed has kilometers per hour, miles per hour, knots and Mach. Then time runs from microseconds to years, and the tool uses a year of 365.25 days.

Also, data storage has two families. Kilobyte and megabyte count in thousands. Kibibyte and mebibyte count in powers of two, so one KiB is 1024 bytes.

Fuel Economy Works In Reverse

First, fuel economy is a special case. Miles per gallon says how far you go on a fuel unit. Liters per 100 kilometers says how much fuel you use on a distance. So a higher number is better in one and worse in the other.

The tool handles that by inverting the value. For example, 30 mpg equals about 7.84 liters per 100 kilometers.

Accuracy And Rounding

The tool works with double precision numbers and exact unit definitions. Then you choose how many significant digits to show, from four to fifteen.

Also, very large and very small results switch to exponent form, so they stay readable.

Handy Numbers To Remember

Some rates come up again and again. One meter is about 3.28 feet. One kilogram is about 2.2 pounds. One liter is about 0.26 US gallons. Also, one inch is exactly 2.54 centimeters.

For temperature, 0 degrees Celsius is 32 Fahrenheit, and 100 degrees Celsius is 212 Fahrenheit. So body temperature of 37 Celsius is about 98.6 Fahrenheit.

For speed, 100 kilometers per hour is about 62 miles per hour. Then 60 miles per hour is about 97 kilometers per hour. Use the tool when you need more digits.

Safe By Design

First, the tool does the maths in your browser and sends nothing. So your numbers stay on your device.