This unit converter handles eight categories of everyday units, from millimetres to miles and from millilitres to gallons. The area section includes land units used in South India, such as the cent and the ground. Results update as you type, and everything runs in your browser.
How to use the unit converter
- Choose a category: length, weight, temperature, area, volume, speed, data or time.
- Type a value and pick the unit you are converting from and to.
- Read the result, which updates live.
- Check the table below it, which shows your value in every unit of that category at once.
| Category | Units |
|---|---|
| Length | mm, cm, m, km, inch, foot, yard, mile |
| Weight | mg, g, kg, tonne, ounce, pound |
| Temperature | °C, °F, K |
| Area | sq ft, sq m, sq yard, cent, ground, acre, hectare, sq km |
| Volume | ml, litre, cubic metre, US gallon, UK gallon, cup (US), teaspoon, tablespoon |
| Speed | km/h, m/s, mph, knot |
| Data | bit, byte, KB, MB, GB, TB (decimal) and KiB, MiB, GiB (binary) |
| Time | seconds up to years |
Indian land units: cent, ground and acre
Property listings in Tamil Nadu, Puducherry and Kerala often use cents and grounds rather than square feet. These units are defined from the acre, and one acre is exactly 43,560 sq ft.
| Unit | In square feet | Notes |
|---|---|---|
| 1 cent | 435.6 sq ft | 1/100 of an acre |
| 1 ground | 2,400 sq ft | Used mainly in Chennai and Tamil Nadu |
| 1 acre | 43,560 sq ft | 100 cents; about 4,046.86 sq m |
| 1 hectare | about 107,639 sq ft | 10,000 sq m; about 2.471 acres |
Watch out: Local practice can differ, and land records may use their own units. For a sale, loan or registration, rely on the area stated in the official land records and documents, and check with the registration office or a lawyer if anything is unclear.
Units that are easy to mix up
- Gallons. A US gallon is about 3.785 litres; a UK (imperial) gallon is about 4.546 litres. Recipes and fuel figures from different countries use different ones.
- KB and KiB. 1 KB is 1,000 bytes; 1 KiB is 1,024 bytes. A “1 TB” drive holds 1,000,000,000,000 bytes, which an operating system using binary units may show as about 931 GiB.
- Bits and bytes. 1 byte is 8 bits. Internet speeds are quoted in bits per second, so a 100 Mbps line moves at most about 12.5 MB of data per second.
- Cups and spoons. The tool uses US customary cups, tablespoons and teaspoons. Cooking measures in other countries can be slightly different.
How temperature conversion works
Most conversions multiply by a fixed factor, but temperature scales have different zero points, so they need a formula. °F = °C × 9 ÷ 5 + 32, and K = °C + 273.15. So 37 °C is 98.6 °F, and 0 °C is 273.15 K.
The international units used here are fixed by agreement: for example, 1 inch is exactly 2.54 cm and 1 pound is exactly 0.45359237 kg. The US NIST unit conversion pages list the exact factors. For quick maths with percentages, try the percentage calculator.
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Frequently asked questions
How many cents are in an acre?
100. One cent is 1/100 of an acre, which is 435.6 sq ft.
How many square feet is one ground?
2,400 sq ft. The ground is used mainly in Chennai and other parts of Tamil Nadu.
Why does my 1 TB drive show less space?
Drive makers use decimal units (1 TB = 1,000,000,000,000 bytes), but some operating systems report sizes in binary units, so the same space appears as about 931 GiB.
Are the results exact?
The conversion factors are exact or very precise, and results are rounded for display. For legal or engineering work, check the rounding you need.