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Unit converters
These converters cover the units people actually need: length, mass, time, temperature and drawing scale. Each one shows the result in every unit at once, not just the single target you picked.
The factors are exact. Imperial units are defined against metric ones by international agreement, so an inch is exactly 2.54 cm and a pound is 0.45359237 kg.
Calculators in this section
Complete alphabetical list · 18
- Area Converterarea converterOpen →
- Clothing Size Converterclothing size converterOpen →
- Cooking Volume Convertercooking converterOpen →
- Currency Convertercurrency converterOpen →
- Data Storage Converterdata storage converterOpen →
- Download Time Calculatordownload time calculatorOpen →
- Energy Converterenergy converterOpen →
- Fuel Economy Converterfuel economy converterOpen →
- Length Converterlength converterOpen →
- Power Converterpower converterOpen →
- Pressure Converterpressure converterOpen →
- Scale Calculatorscale calculatorOpen →
- Shoe Size Convertershoe size converterOpen →
- Speed Converterspeed converterOpen →
- Temperature Convertertemperature converterOpen →
- Time Unit Convertertime converterOpen →
- Volume Convertervolume converterOpen →
- Weight Converterweight converterOpen →
What to keep in mind when converting
- Metric prefixes are powers of ten: kilo is a thousand, centi is a hundredth, milli is a thousandth.
- Imperial units have exact metric definitions, so there is no need to round the factors.
- Temperature is not a simple multiplication: the scales have different zero points.
- Months and years use average lengths, otherwise the result would depend on a specific calendar year.
Frequent conversions
| Question | Answer |
|---|---|
| Centimetres in a metre | 100 cm |
| Centimetres in an inch | 2.54 cm |
| Kilograms in a pound | 0.4536 kg |
| Hours in a day | 24 hours |
| 100 °C in Fahrenheit | 212 °F |
Frequently asked questions
How is a converter different from a calculator?
A converter expresses the same quantity in different units, while a calculator derives a new quantity from a formula.
Why does my result differ from a table I found elsewhere?
Usually because that table rounded the factor. These converters use exact values and round only the displayed result.
Can I enter decimal values?
Yes — use either a dot or a comma as the decimal separator.