Unit Converter

Convert length, weight, temperature, volume, area and speed instantly.

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TL;DR — Unit Converter: A unit converter translates a value from one unit of measurement into another within the same physical quantity — for example, kilometres to miles, kilograms to pounds, Celsius to Fahrenheit. Cal44 supports six categories: length, weight, temperature, volume, area and speed, with common metric, imperial and US units.

What is the Unit Converter?

A unit converter translates a value from one unit of measurement into another within the same physical quantity — for example, kilometres to miles, kilograms to pounds, Celsius to Fahrenheit. Cal44 supports six categories: length, weight, temperature, volume, area and speed, with common metric, imperial and US units.

How to use the Unit Converter

  1. Choose the category (length, weight, temperature, volume, area or speed).
  2. Enter the value and select the source unit.
  3. Select the target unit.
  4. Read the converted value.

Formula

Length: 1 in = 2.54 cm · 1 ft = 0.3048 m · 1 mi = 1.609344 km
Weight: 1 kg = 2.20462 lb · 1 oz = 28.3495 g
Temperature: °F = °C × 9/5 + 32 · K = °C + 273.15
Volume: 1 gal (US) = 3.78541 L · 1 fl oz (US) = 29.5735 mL

Speed: 1 mph = 1.609344 km/h · 1 knot = 1.852 km/h. Area: 1 acre = 4046.86 m² · 1 hectare = 10,000 m².

Worked example

5 miles to kilometres = 5 × 1.609344 = 8.0467 km. 100 °F to °C = (100 − 32) × 5 ÷ 9 = 37.78 °C. 50 kg to lb = 50 × 2.20462 = 110.23 lb.

Frequently asked questions

How do I convert Celsius to Fahrenheit?

°F = °C × 9 ÷ 5 + 32. 20 °C is 68 °F. Going the other way: °C = (°F − 32) × 5 ÷ 9.

How many millilitres in a US cup?

1 US cup = 236.588 mL. 1 metric cup = 250 mL. 1 imperial cup (UK) = 284.131 mL.

What's the difference between US and imperial gallons?

1 US gallon = 3.78541 L. 1 imperial (UK) gallon = 4.54609 L. The imperial gallon is about 20% larger.

How do I convert square metres to square feet?

1 m² = 10.7639 ft². Multiply m² by 10.7639.

Is the unit converter accurate?

Cal44 uses internationally standardised conversion factors. Results are accurate to the displayed precision; for engineering or scientific work, verify against the original SI definitions.

Last updated: 2026-05-24 Free · No signup · Works offline Suggest an improvement