Unit Converter
Convert length, weight, area, volume, speed and temperature instantly, including Korean units like pyeong and geun.
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Unit Converter: complete guide
Walk through the steps and examples, or jump straight to the topic you need.
At a glance
- Supported categories
- Six: length, weight, area, volume, speed and temperature. Add ?type=length, weight, area, volume, speed or temperature to the address and it opens directly on that category.
- Korean units
- Includes pyeong (area), geun (600 g), don (3.75 g) and cup (200 mL) as used in Korea.
- Temperature
- Celsius, Fahrenheit and kelvin are calculated including the offset.
- Absolute zero
- A value below -273.15°C is still calculated, but you are told it is a value that can't exist.
- Displayed digits
- Depending on the size of the value, it shows from 2 to 6 decimal places.
- See together
- Besides the unit you chose, it also shows the results in the other units of the same category.
- Where it runs
- Calculation happens in this browser, and your input is not stored.
How to use Unit Converter
Choose the category first
Choose from length, weight, area, volume, speed and temperature. When you change the category, the usual unit pairing is set automatically. Units from different categories can't be converted into each other.
Enter a value
The result appears as you type. You can use decimal points and thousands commas, and negative numbers too. If you enter something that isn't a number, the tool tells you how to fix it.
Choose the units, and flip them if needed
Choose the unit to convert from and the unit to convert to. Click the middle button and the two units swap, so you can check the reverse calculation right away.
Check the result and copy it
Below it, the results in the other units of the same category appear too. Click Copy result and a sentence including the input value and units is copied, ready to paste into a note or message.
What it’s good for
See a home's floor area in pyeong and square meters
Real estate listings in Korea state area in square meters, but many people get a feel for size in pyeong, the traditional Korean unit of area. Choose pyeong and square meters in the Area category and it converts right away. One pyeong is about 3.3058 square meters, and the tool uses this more accurate value rather than the commonly used 3.3.
Convert overseas specifications to metric units
You can turn the inches and pounds on overseas products into centimeters and kilograms to get a sense of size and weight. It uses the international definitions: exactly 2.54 centimeters per inch and 453.59237 grams per pound.
Worked examples
Seeing an apartment's area in pyeong
Area · 84 square meters → pyeongAbout 25.41 pyeongChecking the weight of an overseas product
Weight · 2.5 pounds → kilogramsAbout 1.1340 kgUnits that are easy to confuse
Swipe the table sideways to see the rest.
| Unit | Basis | Watch out for |
|---|---|---|
| Pyeong | 400/121 square meters (about 3.3058) | Approximating with 3.3 makes the gap grow on large areas. |
| Geun | 600 grams | Some places use a different standard depending on the goods, such as meat or vegetables. |
| Cup | 200 milliliters | A cup in overseas recipes is about 240 mL, so it differs. |
When the result isn’t what you expected
The result is shown in exponent form
When a value is very large or very small, the digits get too long to read. Only then is it shown in exponent form. If you reduce the digits of the input, it appears as an ordinary number.
The temperature is negative but it still calculates
A negative temperature is normal. But if you enter a value below absolute zero, -273.15°C, you are also told it is a value that can't actually exist. The calculation itself is still shown.
The unit I want isn't in the list
Only verified units are included. Units not on the list are not supported. Converting in two steps through a similar unit often gets you the value you want.
Key terms
- Offset
- A value added or subtracted to line up scales with different reference points. It is needed for temperature conversion.
- Absolute zero
- -273.15°C, the lowest temperature in theory. It corresponds to 0 in kelvin.
- Significant digits
- The digits that carry meaning. The number of displayed digits is set according to the size of the value.
Unit Converter FAQ
How many grams is one don of gold?
Choose don (the traditional Korean unit used for gold) in the Weight category and it calculates with 3.75 grams. One geun (a traditional Korean unit of weight) is based on 600 grams. Some industries and goods use different standards, so check before a transaction.
How are the digits of the result decided?
Depending on the size of the value, it shows from 2 to 6 decimal places. Very large or very small values are shown in exponent form.
Can it convert speed too?
In the Speed category it converts between m/s, km/h, mph, knots and ft/s. It uses the international definitions: 1 mile is 1,609.344 m, and 1 knot is 1,852 m per hour.
Can it convert to kelvin?
In the Temperature category you can convert between Celsius, Fahrenheit and kelvin. If you enter a value below absolute zero, it still calculates, but tells you the value can't actually exist.
My pyeong calculation differs a little from another site
Many places approximate 1 pyeong as 3.3. This tool calculates with 400/121, about 3.3058, so the error stays small even on large areas.
Is the value the same if I calculate there and back?
Yes. For every unit, it has been checked that the conversion returns to the original value. Only digits rounded in the display can differ.
Does it save my results?
No. Your input and results exist only on screen and disappear when you reload the page.