Unit Conversion FAQs: Answers to Common Measurement Questions

General Questions

We strive to provide conversions that are reasonably accurate for everyday use. Our conversion formulas use standard conversion factors that are widely accepted.

However, we make no guarantees regarding the accuracy of results. The conversions are intended for general reference only and should not be used for applications where precision is critical.

Length Conversions

There are exactly 2.54 centimeters in 1 inch. This conversion factor is standardized internationally and is used in all precision measurements between metric and imperial systems.

Weight Conversions

There are exactly 453.59237 grams in 1 pound. For cooking or everyday use, 454 grams is often used as a practical approximation.

Temperature Conversions

To convert Fahrenheit to Celsius, subtract 32 from the Fahrenheit value, then multiply by 5/9. The formula is: °C = (°F - 32) × 5/9. For example, 68°F = (68 - 32) × 5/9 = 20°C.

Volume Conversions

The definition of a cup varies by region. In the US, 1 cup equals 236.588 milliliters. In the UK, 1 cup is 284.131 milliliters. In the metric system (used in most countries), 1 cup is standardized as 250 milliliters.

Speed Conversions

To convert kilometers per hour (km/h) to miles per hour (mph), multiply by 0.621371. For example, 100 km/h equals approximately 62.14 mph. This is useful when driving in countries with different speed measurement systems.

Area Conversions

There are 43,560 square feet in 1 acre. An acre is a traditional unit of land area used primarily in the United States and countries with historical ties to the British Empire.

Time Conversions

There are 86,400 seconds in one day (24 hours). This is calculated as: 24 hours × 60 minutes × 60 seconds = 86,400 seconds.

Practical Applications

Miles per gallon (mpg) and liters per 100 kilometers (L/100km) are inversely related. The conversion formula is: L/100km = 235.214583 ÷ mpg (US) or L/100km = 282.48 ÷ mpg (UK). For example, 25 mpg (US) equals approximately 9.4 L/100km.

Learn More About Unit Conversion

Explore our comprehensive guides to master unit conversions: