How do I convert kilometers to miles?

Multiply the number of kilometers by 0.621371. For example, 10 km × 0.621371 = 6.21 miles. Or use this converter for instant results.

How do I convert Celsius to Fahrenheit?

Multiply the Celsius temperature by 9/5, then add 32. Formula: °F = (°C × 9/5) + 32. For example, 25°C = (25 × 1.8) + 32 = 77°F.

How do I convert kilograms to pounds?

Multiply kilograms by 2.20462. For example, 70 kg × 2.20462 = 154.32 lbs.

What is the difference between metric and imperial?

Metric (SI) uses meters, kilograms, liters, and Celsius. Imperial uses feet/inches, pounds/ounces, gallons, and Fahrenheit. Most of the world uses metric; the US, Liberia, and Myanmar primarily use imperial.

How many liters are in a gallon?

One US gallon equals approximately 3.78541 liters. One UK (Imperial) gallon equals approximately 4.54609 liters.

Unit Converter – Free Online Length, Weight, Temperature & Volume Converter

How Unit Conversions Work

Unit conversion is the process of expressing a measurement in a different unit while keeping the same quantity. Most conversions involve multiplying or dividing by a conversion factor — a ratio that relates two units. Temperature conversions are the exception, requiring both multiplication and addition.

Length Conversions

Length is probably the most commonly converted measurement. The metric system uses meters as the base, while the imperial system uses feet and inches. Conversions between the two systems use fixed ratios.

1 mile = 1.60934 km
1 inch = 2.54 cm (exact)
1 meter = 3.28084 feet

Example: Convert 5 miles to kilometers
5 × 1.60934 = 8.047 km

Weight / Mass Conversions

Weight is measured in kilograms (metric) or pounds (imperial). The key conversion factor is that 1 kilogram equals approximately 2.205 pounds.

1 kg = 2.20462 lbs
1 oz = 28.3495 g
1 stone = 6.35029 kg

Temperature Conversions

Unlike other conversions, temperature requires a formula rather than a simple multiplication because the scales have different zero points.

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

Example: Convert 100°F to Celsius
(100 − 32) × 5/9 = 68 × 0.5556 = 37.78°C

Common Reference Table

Conversion	Factor
1 kilometer → miles	0.621371
1 pound → kilograms	0.453592
1 gallon (US) → liters	3.78541
1 acre → square meters	4,046.86
1 mile per hour → km/h	1.60934
1 gigabyte → megabytes	1,024

Frequently Asked Questions

Multiply kilometers by 0.621371. So 10 km = 6.21 miles. Or just type it in above for an instant result.
Use the formula: °F = (°C × 9/5) + 32. For example, 25°C = 77°F. Temperature is the only category that doesn't use a simple multiplication factor.
Multiply kilograms by 2.20462. For example, 70 kg × 2.20462 = 154.32 lbs.
Metric uses meters, kilograms, liters, and Celsius. Imperial uses feet/inches, pounds, gallons, and Fahrenheit. Most of the world uses metric; the US primarily uses imperial.
One US gallon = 3.785 liters. One UK (Imperial) gallon = 4.546 liters. This converter uses US gallons by default.
This converter handles bytes, KB, MB, GB, and TB using the binary standard (1 KB = 1,024 bytes). This matches how operating systems report storage.