Unit Converter

Almost every country in the world officially uses the metric system. The United States, Myanmar, and Liberia are the only three countries that haven't officially adopted it as their primary system. However, metric units are still widely used in the US for scientific, medical, and some commercial purposes. The UK uses a hybrid approach—metric for most things but miles for road distances and pints for beer.

For a quick mental estimate: double the Celsius temperature and add 30. This gives an approximate Fahrenheit value. For example, 20°C: double it (40), add 30 = 70°F (actual is 68°F). For precise conversion, use the formula: °F = (°C × 9/5) + 32. Some easy reference points: 0°C = 32°F (freezing), 100°C = 212°F (boiling), 37°C = 98.6°F (body temperature), and 20°C = 68°F (room temperature).

A US gallon equals approximately 3.785 liters, while a UK (Imperial) gallon equals approximately 4.546 liters—about 20% larger. This means when comparing fuel economy, a car getting 30 MPG in the UK is actually more efficient than one getting 30 MPG in the US. The difference dates back to 1824 when Britain standardized the Imperial gallon based on the volume of 10 pounds of water, while the US kept the older English wine gallon.

This confusion arises because computers use binary (base-2) while humans typically use decimal (base-10). Traditionally, a kilobyte meant 1,024 bytes (2^10), but the "kilo" prefix normally means 1,000. To clarify, the IEC introduced new prefixes: kibibyte (KiB) = 1,024 bytes, mebibyte (MiB) = 1,048,576 bytes. However, the traditional usage persists. Hard drive manufacturers often use decimal (1 GB = 1 billion bytes) while operating systems use binary, which is why a "1 TB" drive shows less space when connected.

A nautical mile (1,852 meters or about 1.151 regular miles) is based on the Earth's geometry—it equals one minute of latitude. This makes navigation calculations much simpler when using charts and coordinates. Knots (nautical miles per hour) are used for ship and aircraft speeds for the same reason. One degree of latitude equals 60 nautical miles, making distance calculations straightforward when navigating by coordinates.

Cooking often requires converting between volume (cups, tablespoons) and weight (grams, ounces). Key conversions: 1 US cup = 237 mL, 1 tablespoon = 15 mL, 1 teaspoon = 5 mL. For weight: 1 cup of flour ≈ 125g, 1 cup of sugar ≈ 200g, 1 cup of butter ≈ 227g. For precise baking, weighing ingredients in grams is more accurate than using volume measurements, which is why professional recipes often use weight.