How Unit Conversion Works
Unit conversion uses a ratio between two units of the same type. Most conversions multiply or divide by a fixed factor. Temperature is the exception — it requires formulas because the scales have different zero points.
Length Conversions
Common length conversions between metric and imperial systems:
- 1 kilometer = 0.6214 miles
- 1 mile = 1.6093 kilometers = 5,280 feet
- 1 meter = 3.2808 feet = 39.37 inches
- 1 foot = 0.3048 meters = 12 inches
- 1 inch = 2.54 centimeters
Temperature Formulas
- °C to °F: °F = (°C × 9/5) + 32
- °F to °C: °C = (°F − 32) × 5/9
- °C to K: K = °C + 273.15
- K to °C: °C = K − 273.15
Key reference points: water freezes at 0°C / 32°F / 273.15K and boils at 100°C / 212°F / 373.15K.
Area Conversions
- 1 acre = 43,560 sq ft = 4,046.86 sq m
- 1 hectare = 10,000 sq m = 2.471 acres
- 1 sq mile = 640 acres = 2.59 sq km
- 1 sq meter = 10.764 sq ft
Volume Conversions
- 1 gallon (US) = 4 quarts = 8 pints = 16 cups = 3.785 liters
- 1 liter = 33.814 fl oz = 4.227 cups
- 1 cubic meter = 1,000 liters = 264.17 gallons
- 1 tablespoon = 3 teaspoons = 14.79 ml
Weight Conversions
- 1 kilogram = 2.2046 pounds
- 1 pound = 16 ounces = 453.59 grams
- 1 stone = 14 pounds = 6.35 kg
- 1 metric ton = 1,000 kg = 2,204.6 pounds