Quick answer
1 inch = 2.54 cm, 1 pound = 0.45359237 kg, °F = °C × 9 ÷ 5 + 32 and 1 GiB = 1,073,741,824 bytes. Pick a quantity, type a number into either box and the other updates instantly; the table below shows the same value in every unit of that kind.
How does unit conversion work?
Convert between eight kinds of quantity: length, weight, area, volume, temperature, speed, data size and time. Alongside metric and imperial units it includes the Vietnamese units people still use every day, such as the lạng, yến and tạ for weight, chỉ and lượng for gold, and the regional land units sào, mẫu and công. Results are rounded to remove floating-point noise.
How to convert units
- 1
Pick a quantity: Length, Weight, Area, Volume, Temperature, Speed, Data or Time.
- 2
Choose the units in “From” and “To”.
- 3
Type a number into either box: the other one converts instantly, no button needed. Use the arrow button to swap directions.
- 4
Check “Every unit at once” below for the same value in every unit of that kind, and click “Copy” to take the result.
Common conversions
| Convert | Result | Tip |
|---|---|---|
| 1 inch | 2.54 cm | A 6.1-inch screen is about 15.5 cm corner to corner |
| 1 foot | 30.48 cm | 1 foot = 12 inches |
| 1 mile | 1.609344 km | 60 mph ≈ 96.6 km/h |
| 1 pound | 453.59237 g | 1 kg ≈ 2.2 lb |
| 0 °C / 100 °C | 32 °F / 212 °F | °F = °C × 9 ÷ 5 + 32 |
| 1 GB / 1 GiB | 1,000,000,000 / 1,073,741,824 bytes | Drives are sold in GB, Windows reports GiB, so they look “smaller” |
Vietnamese units
Traditional units you will meet in Vietnamese markets, jewellers and land listings.
| Unit | Equals | Used for |
|---|---|---|
| 1 lạng | 100 g | Meat and vegetables at the market |
| 1 yến / 1 tạ | 10 kg / 100 kg | Rice and farm produce |
| 1 chỉ (gold) | 3.75 g | Jewellery; 10 chỉ = 1 lượng |
| 1 lượng / cây (gold) | 37.5 g | Gold bars |
| 1 sào (northern) | 360 m² | Farmland in the north; 10 sào = 1 mẫu |
| 1 sào (central) | about 500 m² | Farmland in the centre |
| 1 công (southern) | 1,000 m² (or 1,296 m² for công tầm cấy) | Farmland in the Mekong Delta |
Land units are local customs and vary by area; property documents always use square metres.
Real-world examples
A US recipe in grams
Volume, 1 US cup to millilitres gives about 236.6 ml; switch to Weight for butter in ounces (1 oz ≈ 28.35 g).
A 1 TB drive shows 931 GB
Data, 1 terabyte to gibibytes gives about 931.32 GiB: Windows labels it GB but counts in GiB.
Weather in Fahrenheit
Temperature, 86 °F to Celsius gives 30 °C; the formula is subtraction and scaling, not a single multiplication.
Buying land in the Mekong Delta
Area, 15 công to square metres gives 15,000 m² (1.5 ha) with the 1,000 m² công, or 19,440 m² with công tầm cấy, so check which one the seller means.
Common problems
- Typing 1,500 on the Vietnamese page gives 1.5.
- The Vietnamese page reads a dot as the thousands separator and a comma as the decimal point. On the English page, 1,500 means one thousand five hundred.
- Temperatures come out wrong when scaled.
- Temperature is not a simple ratio: 0 °C is 32 °F, not 0. The tool uses the proper offset formula.
- “Below absolute zero”.
- The lowest possible temperature is 0 K = −273.15 °C = −459.67 °F. Check the minus sign you typed.
- Months and years look off by a few hours.
- They are averages (a year of 365.2425 days). For the exact number of days between two dates, use a date calculator.
How the converter calculates
Every unit is defined by an exact factor relative to a base unit for its group (metre, kilogram, square metre, litre, metre per second, byte, second). Converting from A to B multiplies by A's factor and divides by B's. International units use their exact definitions, such as 1 inch = 0.0254 m and 1 pound = 0.45359237 kg.
Temperatures convert through kelvin with the offset formulas. Results are rounded to 12 significant digits so you never see artefacts like 0.30000000000000004.
Glossary
- KB vs KiB
- KB is 1,000 bytes (decimal); KiB is 1,024 bytes (binary). Likewise MB / MiB and GB / GiB.
- Nautical mile
- Used at sea and in the air, exactly 1,852 m; one nautical mile per hour is a knot.
- Imperial vs US gallon
- The UK (imperial) gallon is 4.54609 l, the US gallon 3.785411784 l.
- Sào, mẫu, công
- Traditional Vietnamese land units whose size depends on the region (360 to about 500 m² for a sào, 1,000 or 1,296 m² for a công).
Frequently asked questions
How many centimetres are in an inch?
Exactly 2.54 cm; a foot is 30.48 cm.
How do I convert Celsius to Fahrenheit?
°F = °C × 9 ÷ 5 + 32. For example 37 °C = 98.6 °F; −40 is the one temperature that is the same on both scales.
Why does a 500 GB drive show about 465 GB?
Manufacturers count 1 GB as 1,000,000,000 bytes, while Windows counts in GiB (1,073,741,824 bytes) but labels them GB. 500 GB ≈ 465.66 GiB.
How many grams is a chỉ of gold?
3.75 g. A lượng (also called a cây) is 10 chỉ, or 37.5 g.
Are the conversions exact?
Yes for the defined units; results are shown to 12 significant digits. Regional land units follow the most common local values.
Is anything I type stored?
No. Conversions run in your browser and nothing is sent anywhere.
Ratings and comments
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