Why Do You Need a Unit Converter?
In a globalized world, it's common to encounter different measurement systems. While most countries use the International System (SI) or metric system, the United States and some other countries use the imperial system. Our converter helps you translate between these systems instantly.
Conversion Categories
Length
Length is probably the most frequent conversion. From miles to kilometers to understand distances on maps, to feet and inches to interpret product measurements.
1 mile = 1.609 km 1 foot = 30.48 cm 1 inch = 2.54 cm 1 yard = 0.9144 m
Weight (Mass)
Weight conversions are essential for cooking, nutrition, international shipping, and medicine.
1 pound (lb) = 0.4536 kg 1 ounce (oz) = 28.35 g 1 stone = 6.35 kg 1 metric ton = 1000 kg
Temperature
Unlike other units, temperature doesn't use simple multiplicative factors. Each scale has a different zero point.
°F = (°C × 9/5) + 32 °C = (°F - 32) × 5/9 K = °C + 273.15
For a rough mental Celsius to Fahrenheit conversion: double the value and add 30. For example, 20°C ≈ 70°F (exact: 68°F).
Volume
Volume conversions are particularly important in cooking and for understanding fuel prices in different countries.
- 1 US gallon = 3.785 liters
- 1 UK gallon = 4.546 liters (20% more than US!)
- 1 cup = 236.6 ml
- 1 fluid ounce = 29.57 ml
Area
From square meters for real estate to hectares for agricultural land.
- 1 hectare = 10,000 m² ≈ 2.47 acres
- 1 acre = 4,046.86 m²
- 1 ft² = 0.0929 m²
Speed
Fundamental for travelers driving in countries with different systems.
- 1 km/h = 0.6214 mph
- 1 mph = 1.609 km/h
- 1 knot = 1.852 km/h
To mentally convert km/h to mph, multiply by 0.6 (or divide by 1.6). Example: 100 km/h ≈ 62 mph.
International System vs. Imperial System
The International System of Units (SI) is the worldwide standard used by the vast majority of countries. Only three countries officially use the imperial system for everyday measurements: the United States, Liberia, and Myanmar.
In Latin America, all countries use the metric system, but it's common to find imperial references in contexts like construction (inches for pipes), nutrition (ounces on imported products), and American cooking recipes.
In physics, mass (kilograms) measures the amount of matter, while weight (newtons) is the gravitational force. In everyday life, we use "weight" to refer to mass. On Earth's surface, 1 kg of mass weighs approximately 9.81 newtons.
The US attempted to adopt the metric system in the 1970s, but the effort was voluntary and never completed. Industrial inertia, conversion costs, and habit make the change difficult, although many industries (science, medicine, military) already use the metric system.
Yes, one degree Celsius is exactly equal to one kelvin. The only difference is the zero point: 0°C = 273.15 K. Kelvin doesn't use the degree symbol (°).