Unit converter
Convert length, area (including pyeong), weight, volume, and temperature in your browser.
Numbers you enter never leave this device.
How to use it
- 1
Pick a category
Choose length, area, weight, volume, or temperature. The unit lists below change to match the category you picked.
- 2
Type a value
Enter a number such as 12.5 or -40. Thousands separators are accepted, and the result updates as you type.
- 3
Choose the two units
Select the unit you have and the unit you want. Use the swap button to reverse them in one click when you need the opposite direction.
- 4
Read every unit at once
Under the main result, a list shows the same value in every unit of the category, so you can compare square meters, pyeong, and square feet side by side.
Common use cases
Security and privacy
Your numbers stay in this tab
The conversion is plain arithmetic done by browser code on your device. No upload route exists for this tool, no request carries what you type, and nothing is stored after you close the tab. Results are rounded to ten significant digits only for display, so floating-point noise such as 0.30000000000000004 does not appear.
Supported inputs and outputs
Supported units
- Length: mm, cm, m, km, inch, foot, yard, mile
- Area: cm², square meter, pyeong, hectare, square kilometer, square foot, acre
- Weight: mg, g, kg, metric ton, ounce, pound
- Volume: mL, L, cubic meter, US fluid ounce, US cup, US gallon
- Temperature: Celsius, Fahrenheit, kelvin
FAQ
How many square meters is one pyeong?
One pyeong is 400/121 square meters, about 3.305785 square meters, from its definition as a square of 6 ja per side (1 ja = 10/33 m). Frisbly uses that exact fraction, not a rounded 3.3.
Which definitions are used?
One inch is exactly 25.4 mm and one pound is exactly 0.45359237 kg, from the 1959 international agreement. One US gallon is exactly 3.785411784 liters, and Fahrenheit is Celsius times 9/5 plus 32.
Why are the cup and gallon labeled US?
Volume units with the same name differ by country. The cup, fluid ounce, and gallon here are US customary units, not British imperial ones.
Can I use the result in a contract or filing?
The numbers follow the official definitions. Before you copy a result into a contract or filing, check which unit and how many decimal places that document asks for.
Is anything I type uploaded?
No. The calculation happens in your browser and no request that carries your input is sent to Frisbly or anyone else.