Unit Converter

Unit Conversion: A Complete Guide

Unit conversion is the process of changing a measurement from one unit to another without changing the actual quantity. Whether you are cooking with a recipe from another country, working on a science problem, or traveling abroad, the ability to convert between units quickly is invaluable.

The Metric System vs. Imperial System

The metric system (International System of Units, or SI) is used by the vast majority of the world. It is based on powers of 10, making conversions within the system straightforward: 1 kilometer = 1,000 meters, 1 kilogram = 1,000 grams, and so on. The imperial system, still commonly used in the United States, Liberia, and Myanmar, uses units like inches, feet, pounds, and gallons with less predictable conversion factors.

Common Conversion References

• Length: 1 inch = 2.54 cm, 1 mile = 1.609 km, 1 foot = 30.48 cm
• Weight: 1 pound = 0.4536 kg, 1 ounce = 28.35 g, 1 stone = 14 pounds
• Temperature: °F = (°C × 9/5) + 32, 0°C = 32°F, 100°C = 212°F
• Volume: 1 US gallon = 3.785 liters, 1 cup = 236.6 ml
• Area: 1 acre = 43,560 sq ft = 4,047 sq m
• Speed: 1 mph = 1.609 km/h, 1 knot = 1.151 mph
• Digital: 1 KB = 1,024 bytes, 1 MB = 1,024 KB, 1 GB = 1,024 MB

Temperature Conversion

Temperature is unique because the scales do not share a zero point, so conversion requires both multiplication and addition. The key formulas are:

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

Some easy reference points: water freezes at 0°C / 32°F / 273.15 K, and boils at 100°C / 212°F / 373.15 K. Body temperature is approximately 37°C / 98.6°F.

Digital Storage Units

Digital storage uses binary prefixes where each step is a factor of 1,024 (2¹&sup0;), not 1,000. This means 1 GB is actually 1,073,741,824 bytes. Some standards use "gibibyte" (GiB) for the binary value and "gigabyte" (GB) for the decimal value (1,000,000,000 bytes), but in practice most operating systems and this calculator use the binary definition.