Author
BetterProduct Editorial Team
Unit conversion is a fundamental skill in science, cooking, travel, and everyday life. The world uses two main measurement systems: the metric system (used by most countries) and the imperial system (used primarily in the US). Understanding how to convert between them — and within each system — prevents costly mistakes and helps you communicate measurements clearly.
BetterProduct Editorial Team
Checked against standard math or conversion logic and browser-side calculation behavior.
March 2026
Quick everyday calculations and unit checks.
7 language editions aligned from the same source formulas.
Metric: 1 km = 1,000 m = 100,000 cm = 1,000,000 mm. Imperial: 1 mile = 1,760 yards = 5,280 feet = 63,360 inches. Cross-system: 1 inch = 2.54 cm; 1 foot = 30.48 cm; 1 meter = 3.281 feet; 1 mile = 1.609 km. Quick approximation: multiply km by 0.6 to get miles (or miles by 1.6 to get km).
Metric: 1 kg = 1,000 g = 1,000,000 mg. Imperial: 1 pound = 16 ounces; 1 ton = 2,000 pounds. Cross-system: 1 pound = 0.4536 kg; 1 kg = 2.205 pounds; 1 ounce = 28.35 g. Quick approximation: multiply kg by 2.2 to get pounds (or divide pounds by 2.2 to get kg).
Celsius to Fahrenheit: °F = (°C × 9/5) + 32. Fahrenheit to Celsius: °C = (°F − 32) × 5/9. Key reference points: 0°C = 32°F (water freezes); 100°C = 212°F (water boils); 37°C = 98.6°F (body temperature); 20°C = 68°F (comfortable room temperature). Quick approximation: double the Celsius temperature and add 30 to get approximate Fahrenheit.
Metric: 1 liter = 1,000 ml. Imperial: 1 gallon = 4 quarts = 8 pints = 16 cups = 128 fluid ounces. Cross-system: 1 liter = 0.264 gallons = 33.8 fl oz; 1 gallon = 3.785 liters; 1 cup = 240 ml. Cooking: 1 tablespoon = 3 teaspoons = 15 ml; 1 cup = 16 tablespoons = 240 ml.