Unit Converter FAQ: Common Conversion Questions

The formula is: °F = (°C × 9/5) + 32. So 100°C (boiling water) = 212°F, and 0°C (freezing) = 32°F. For a quick mental estimate, double the Celsius value and add 30. Use our free Temperature Converter for any temperature unit including Kelvin.

1 meter = 3.28084 feet. Conversely, 1 foot = 0.3048 meters. The metric system is used in most countries; the imperial system (feet, inches, miles) is primarily used in the United States. Convert any length unit instantly — meters, feet, inches, centimeters, miles, kilometers, and more.

1 kilogram = 2.20462 pounds. To convert kg to lbs, multiply by 2.20462. To convert lbs to kg, divide by 2.20462 (or multiply by 0.453592). Use our free Weight Converter for kg, lbs, ounces, grams, stones, and more.

In base-2 (binary), 1 gigabyte (GB) = 1,024 megabytes (MB). In base-10 (SI), 1 GB = 1,000 MB. Hard drive manufacturers use base-10, which is why a "500 GB" drive appears slightly smaller on your computer. Convert between all data storage units — bits, bytes, KB, MB, GB, TB.

1 mph = 1.60934 km/h. To convert mph to km/h, multiply by 1.60934. To go the other way, multiply km/h by 0.621371. Speed limits in the US are in mph; most other countries use km/h. Convert speed units instantly here.

1 acre = 4,046.86 square meters. Area conversion is common in real estate, agriculture, and land planning. Other useful conversions: 1 sq km = 247.105 acres; 1 hectare = 2.471 acres. Convert area units for free here.

A fluid ounce (fl oz) measures volume (liquids), while a dry ounce measures weight (solids). 1 US fluid ounce ≈ 29.5735 mL. 1 dry ounce ≈ 28.3495 grams. They are not interchangeable. Convert volume units or weight units with our free tools.

Roman numerals use letters: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. When a smaller value precedes a larger one (like IV), it is subtracted. So IV=4, IX=9, XL=40, CM=900. MCMXCIX = 1999. Convert Roman numerals instantly.