Unit Converter

Convert length, weight, temperature, area, volume, speed, pressure, time, energy, and digital storage units instantly. Supports metric, imperial, and US customary units — 200+ conversion pairs, formula shown for every result.

What is a Unit Converter?

A unit converter is a tool that translates a measurement expressed in one unit into its equivalent in another unit. The world uses two primary measurement systems — the metric system (SI), used by most countries, and the imperial / US customary system, still used widely in the United States, the UK for some purposes, and in trade contexts globally. Converting between them — kilograms to pounds, kilometres to miles, Celsius to Fahrenheit — is a daily need for students, travellers, engineers, cooks, and fitness enthusiasts.

This converter supports ten categories and over 200 unit pairs. Every result includes the conversion formula so you understand how the number was derived, not just what it is. All calculations run in your browser — no data is sent to any server. The calculator also supports an embeddable iframe widget so bloggers, teachers, and developers can embed any category on their own website with a single line of HTML.

Conversion Formulas Reference

LENGTH

1 inch = 2.54 cm
1 foot = 30.48 cm
1 mile = 1.60934 km
1 yard = 0.9144 m
1 nautical mile = 1.852 km

WEIGHT

1 kg = 2.20462 lbs
1 lb = 0.453592 kg
1 oz = 28.3495 g
1 stone = 6.35029 kg
1 metric tonne = 1000 kg

TEMPERATURE

°F = (°C × 9/5) + 32
°C = (°F − 32) × 5/9
K = °C + 273.15

AREA

1 hectare = 10,000 m²
1 acre = 4,046.86 m²
1 sq ft = 0.092903 m²
1 sq mile = 2.58999 km²

VOLUME

1 litre = 0.264172 US gallons
1 US gallon = 3.78541 litres
1 fl oz (US) = 29.5735 ml
1 cup (US) = 236.588 ml

SPEED

1 mph = 1.60934 km/h
1 knot = 1.852 km/h
1 m/s = 3.6 km/h

PRESSURE

1 bar = 100,000 Pa
1 atm = 101,325 Pa
1 psi = 6,894.76 Pa
1 mmHg = 133.322 Pa

TIME

1 hr = 3,600 s
1 day = 86,400 s
1 year ≈ 31,536,000 s (365 days)

ENERGY

1 kcal = 4,184 J
1 kWh = 3,600,000 J
1 BTU = 1,055.06 J

DIGITAL STORAGE

1 KB = 1,024 bytes
1 MB = 1,024 KB = 1,048,576 bytes
1 GB = 1,024 MB
1 TB = 1,024 GB

Common Conversion Reference Tables

Weight — Kilograms to Pounds
1kg=2.205lb5kg=11.023lb10kg=22.046lb25kg=55.116lb50kg=110.231lb70kg=154.324lb80kg=176.37lb100kg=220.462lb
Temperature — Celsius to Fahrenheit
-40°C=-40°F0°C=32°F10°C=50°F20°C=68°F25°C=77°F37°C=98.6°F100°C=212°F180°C=356°F
Length — Centimetres to Inches
1cm=0.394in2.54cm=1in5cm=1.969in10cm=3.937in30cm=11.811in100cm=39.37in150cm=59.055in180cm=70.866in
Distance — Kilometres to Miles
1km=0.621mi5km=3.107mi10km=6.214mi21.1km=13.109mi42.2km=26.219mi50km=31.069mi100km=62.137mi200km=124.274mi

Length Converter — Metric and Imperial

People often need to convert length units for travel, construction, or recipe sizing. Common pairs include cm to inches, meters to feet, km to miles, mm to inches, and yards to metres. The most searched length conversion globally is cm to inches (1 cm = 0.3937 inches) and km to miles (1 km = 0.621371 miles).

Weight Converter — kg, lbs, grams, stone, ounces

Weight conversions are crucial for gym routines, cooking, shipping, and medical dosages. Remember that 1 kilogram = 2.20462 pounds. To convert lbs to kg, divide by 2.20462. Stone is used in the UK and Ireland for body weight — 1 stone = 14 lbs = 6.35 kg.

Temperature Converter — Celsius, Fahrenheit, Kelvin

The Celsius scale is used almost everywhere, while Fahrenheit is primary in the USA. Kelvin is used in scientific contexts. To convert between them, use these formulas: °F = (°C × 9/5) + 32, °C = (°F − 32) × 5/9, and K = °C + 273.15. Keep in mind that 37°C = 98.6°F (normal human body temperature) and 0°C = 32°F (freezing point of water).

Digital Storage Converter — Bits, Bytes, KB, MB, GB, TB

Digital storage conversion can be confusing due to binary prefix (1 KB = 1,024 bytes) vs SI prefix (1 kB = 1,000 bytes). This is why storage manufacturers use SI (making drives seem larger) while operating systems use binary. Common searches include MB to GB, GB to TB, and bits to bytes.

Embed This Unit Converter on Your Website

You can embed any category of this unit converter on your website, blog, or app for free using an iframe. When visitors use the embedded calculator they see a Powered by GoToCalc link. No API key required.

<iframe 
  src="https://gotocalc.online/tools/unit-converter?embed=1&category=length" 
  width="100%" 
  height="480" 
  frameborder="0" 
  style="border-radius:12px;border:1px solid #e5e5e5"
  title="Unit Converter by GoToCalc"
></iframe>

Note that category can be replaced with: weight, temperature, area, volume, speed, pressure, time, energy, storage.

People Also Ask

How do I convert kg to lbs?
Multiply the kilogram value by 2.20462. For example, 70 kg × 2.20462 = 154.32 lbs. To convert in reverse (lbs to kg), divide by 2.20462 or multiply by 0.453592.
How do I convert Celsius to Fahrenheit?
Use the formula °F = (°C × 9/5) + 32. For example, 25°C = (25 × 1.8) + 32 = 77°F. The freezing point of water is 0°C = 32°F; normal body temperature is 37°C = 98.6°F.
How do I convert km to miles?
Multiply kilometres by 0.621371. For example, 10 km × 0.621371 = 6.21 miles. To convert miles to km, multiply by 1.60934.
How do I convert cm to inches?
Divide centimetres by 2.54. For example, 30 cm ÷ 2.54 = 11.81 inches. Alternatively, multiply by 0.3937. To convert inches to cm, multiply by 2.54.
What is the difference between metric and imperial units?
The metric system (SI) uses base-10 units — metres, kilograms, litres, Celsius — and is the official standard in most of the world. The imperial system uses feet, pounds, gallons, and Fahrenheit and is still primary in the United States and partly in the UK. Converting between them requires fixed mathematical factors.
How do I convert Fahrenheit to Celsius?
Use the formula °C = (°F − 32) × 5/9. For example, 98.6°F = (98.6 − 32) × 5/9 = 37°C.
How many KB in a MB, and MB in a GB?
1 megabyte (MB) = 1,024 kilobytes (KB). 1 gigabyte (GB) = 1,024 MB = 1,048,576 KB. Storage manufacturers sometimes use 1,000-based (SI) prefixes, which is why a "500 GB" drive may show as 465 GB in your OS.
How do I convert mph to km/h?
Multiply mph by 1.60934. For example, 60 mph × 1.60934 = 96.56 km/h. To convert km/h to mph, multiply by 0.621371.
How do I convert litres to gallons?
For US gallons, multiply litres by 0.264172 (1 litre = 0.264172 US gallons). For UK (imperial) gallons, multiply by 0.219969 (1 litre = 0.219969 UK gallons). To convert gallons to litres (US), multiply by 3.78541.
How do I convert square feet to square metres?
Multiply sq ft by 0.092903. For example, 500 sq ft × 0.092903 = 46.45 m². To convert m² to sq ft, multiply by 10.7639.
How do I convert ml to fl oz?
Divide ml by 29.5735 (US fluid ounce). For example, 250 ml ÷ 29.5735 = 8.45 fl oz. To convert fl oz to ml, multiply by 29.5735.
Can I embed this unit converter on my website?
Yes, free of charge. Use the embed panel inside the converter to copy the iframe code. You can specify which category to show by default using the category= parameter in the URL. No API key or registration needed. The embed includes a small "Powered by GoToCalc" attribution link.

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