How do I convert Fahrenheit to Celsius?

Formula: °C = (°F - 32) × 5/9. For example, 98.6°F = (98.6 - 32) × 5/9 = 37°C.

What units can I convert?

Length (m, km, mi, ft, in, cm, mm, nm), Weight (kg, g, mg, lb, oz, ton), Temperature (°C, °F, K), Volume (L, mL, gal, fl oz, cup, pt, qt), Speed (m/s, km/h, mph, knot), Area (m², km², ft², mi², acre, ha), Data (B, KB, MB, GB, TB, PB).

What is the exact formula to convert cm to inches?

Divide centimetres by 2.54, because one inch is defined as exactly 2.54 cm under the international agreement adopted in 1959. So 30 cm ÷ 2.54 = 11.81 inches. To go the other way, multiply inches by 2.54 to get centimetres.

How do I convert kilograms to pounds?

Multiply kilograms by 2.20462262. One pound equals exactly 0.45359237 kg by international definition, so 1 kg is about 2.2046 lb. For example, 70 kg × 2.20462 = 154.32 lb. To reverse it, multiply pounds by 0.45359237 to get kilograms.

How many decimal places should I round a conversion to?

It depends on context. For body height or weight, one decimal place is plenty (175.3 cm, 68.0 kg). For engineering or scientific work, keep more digits to limit rounding error. This tool computes full precision, and you can round the displayed result to suit your needs.

Why is metric easier to convert than imperial units?

Metric units scale by powers of ten — 1 km = 1,000 m, 1 m = 100 cm — so converting is just shifting the decimal point. Imperial units use irregular factors (12 inches per foot, 16 ounces per pound) that must be memorised, making conversions slower and more error-prone.

How do I check whether my luggage meets an airline weight limit?

Convert the limit and your bag weight to the same unit first. A common 23 kg checked-bag limit equals about 50.7 lb (23 × 2.20462), and a 7 kg cabin limit is about 15.4 lb. Weigh your bag, convert, and compare against the airline stated figure.

Unit Converter — Length, Weight, Temperature

How to use Unit Converter

The unit converter handles length, weight, temperature, area, volume, speed, time, data and energy conversions — all within a single interface. Enter a value and source unit; the result appears in all compatible units simultaneously. Supports both metric and imperial systems with full precision and scientific notation for very large or small values.

Select a unit category (e.g. Length, Temperature).
Enter a numeric value in the source unit input.
Select the source unit from the dropdown.
All target unit values update instantly — copy any result with one click.

Your data never leaves your device — 100% private processing.

Metric vs imperial and everyday conversions

The metric system uses decimal multiples (kilo = 1,000, milli = 0.001) making conversions between metric units trivial. The imperial system (miles, feet, pounds, Fahrenheit) uses arbitrary conversion factors that must be memorised. Common cross-system conversions: 1 inch = 2.54 cm, 1 mile = 1.609 km, 1 kg = 2.205 lbs, 1 litre = 0.264 US gallons. Temperature conversion requires an offset: °C = (°F − 32) × 5/9.

Common unit conversions
Metric	Imperial	Factor
1 km	0.621 miles	× 0.621371
1 kg	2.205 lbs	× 2.20462
1 litre	0.264 US gal	× 0.264172
1 m²	10.764 ft²	× 10.7639
0°C	32°F	× 9/5 + 32

Data size units explained

Data size has two parallel standards. The SI decimal standard: 1 kilobyte (KB) = 1,000 bytes, 1 megabyte (MB) = 1,000,000 bytes. The IEC binary standard: 1 kibibyte (KiB) = 1,024 bytes, 1 mebibyte (MiB) = 1,048,576 bytes. Hard drive manufacturers use decimal, while RAM and operating systems traditionally use binary. This tool uses binary (1 KB = 1,024 bytes) for data conversions by default.

Worked examples

Centimetres to inches

Inputs: 30 cm to inches

Result: 11.81 in

Kilograms to pounds

Inputs: 70 kg to pounds

Result: 154.32 lb

Celsius to Fahrenheit

Inputs: 100°C to Fahrenheit

Result: 212°F

Glossary

SI unit: International System of Units — the modern metric system.
Imperial unit: Traditional units used mainly in the United States (inches, pounds, Fahrenheit).
Conversion factor: The ratio used to convert one unit to another.
Derived unit: A unit formed from base SI units by multiplication or division, e.g. m/s for speed.

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Unit Converter

Common conversions

How to use Unit Converter

Metric vs imperial and everyday conversions

Data size units explained

Worked examples

Glossary

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Frequently Asked Questions

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