Unit Converter

This is a browser-based converter for common units of measurement, organized into six categories: length, weight, area, volume, speed and temperature. Type a number, pick the unit you are converting From and the unit you are converting To, and the result shows up immediately below. There is no calculate button. It only converts numbers between units; it does not check whether your value makes sense, and it does not cover currency, time or digital storage. The arithmetic runs in your own browser, and the page does not send the numbers you type to any server.

How to use it

1. Choose a category with the buttons at the top: Length, Weight, Area, Volume, Speed or Temperature. Switching category resets From and To to the first two units in that category's list.
2. Enter the number you want to convert in the Value field. Integers, decimals and negative numbers are accepted; negatives mostly matter for temperature.
3. Pick your starting unit in the From dropdown and the target unit in the To dropdown.
4. Read the number in the Result box. It refreshes as soon as you change the value or either dropdown. If the field is empty or not a valid number, the result shows a dash.

Units in each category

• Length: meter, kilometer, centimeter, millimeter, micrometer, nanometer, mile, yard, foot, inch, nautical mile, light-year, plus the traditional Chinese li, chi and cun.
• Weight: kilogram, gram, milligram, metric ton, pound, ounce, stone, carat, plus the Chinese jin and liang.
• Area: square meter, square kilometer, square centimeter, square millimeter, hectare, mu (Chinese), acre, square foot, square inch, square mile, square yard.
• Volume: liter, milliliter, cubic meter, cubic centimeter, gallon, pint, quart, fluid ounce, cubic foot, cubic inch.
• Speed: m/s, km/h, mph, knot, ft/s, Mach.
• Temperature: Celsius, Fahrenheit, Kelvin.

Worked examples (computed with the tool's own logic)

Converting 1 mile to kilometers gives 1.609344. Converting 6 feet to meters gives 1.8288. Converting 10 pounds to kilograms gives 4.5359237, and 100 km/h to mph gives 62.13711922. For temperature, 37 Celsius is 98.6 Fahrenheit, 98.6 Fahrenheit converts back to 37 Celsius, 0 Celsius is 273.15 Kelvin, and -40 Celsius equals -40 Fahrenheit. These come from the same method the page uses: the value is first converted to the category's base unit (meter for length, kilogram for weight, square meter for area) and then divided by the target unit's factor.

Limits and known quirks

• Results keep 10 significant digits (4 decimal places for temperature) and trailing zeros are dropped. Very small or very large results may appear in scientific notation, e.g. 1 nanometer in meters shows 1e-9.
• The mu, chi, cun, km/h and knot factors are exact fractions (e.g. 1 mu = 2000/3 square meters), so 1 hectare converts to exactly 15 mu. A few other factors, such as Mach, remain approximations.
• Mach uses a fixed 340.29 m/s, roughly the speed of sound at sea level in standard conditions. Real values change with temperature and altitude, and the tool does not adjust for that.
• Jin is treated as 0.5 kg and liang as 0.05 kg. Gallon, pint, quart and fluid ounce use US liquid measures (one gallon is about 3.785 liters), not imperial ones.
• Temperature conversion does not check for absolute zero. You can enter values below 0 Kelvin and still get a number, though it has no physical meaning.
• Only one value can be converted at a time. There is no batch input and no copy button, so you need to select the result text yourself.

How many mu is one hectare?

One mu is 2000/3 square meters (about 666.67), so 1 hectare is exactly 15 mu and the page shows 15. For legal use such as a land contract, rely on the figure in the official document.

What is the difference between US and imperial units?

For length and mass, the mile, foot, inch, pound and ounce are effectively the same in both systems, and the tool uses the international definitions (1 inch = 0.0254 m, 1 pound = 0.45359237 kg). The difference shows up in capacity units, where a US gallon is smaller than an imperial gallon. The Volume category here uses US values, so keep that in mind with British recipes or fuel figures.

Why is temperature conversion not just a multiplication?

Celsius and Fahrenheit have different zero points, so one factor is not enough. The formula is Fahrenheit = Celsius x 9 / 5 + 32, and in reverse Celsius = (Fahrenheit - 32) x 5 / 9. Kelvin is Celsius plus 273.15. The tool always converts to Celsius first and then to the target scale, so any direction among the three works.

Can I convert between categories, such as kilograms to liters?

No. Each category converts only within itself, because the relationship between mass and volume depends on the density of the substance, and water and oil differ. For recipe conversions between volume and weight you need the density of the specific ingredient.

Privacy and processing

The conversion is plain arithmetic in the page's own script, running in your browser. The values and units you choose are not uploaded and the tool does not store them. If you reload the page, the value field returns to its default of 1.