 Info ### Conversions

#### Length

1 inch = 2.54 centimeters (exactly)
1 centimeter = 0.394 inches
1 foot = 0.305 meters
1 mile = 5280 feet = 1.61 kilometers
1 kilometer = 1000 meters = 0.621 miles
1 light year = 9.46 x 10^12 kilometers = 5.88 X 10^12 miles = 0.307 parsec

#### Area

1 square inch = 0.00694 square feet = 6.45 square centimeters
1 square foot = 144 square inches = 0.0929 square meters
1 square mile = 640 acres = 2.59 square kilometers

#### Velocity Speed

1 ft/s = 0.305 m/s
1 mile/hour = 1.47 ft/s = 1.61 kilometer/hour = 0.447 m/s
1 m/s = 1000 cm/s = 3.28 ft/s
1 kilometer/hour = 0.278 m/s = 0.621 miles/hour = 0.912 ft/s
Speed of light = 3.00 x 10^8 m/s = 186,000 miles/second
Speed of sound in air ar 0 degrees C = 331 m/s = 10909 ft/s = 741 miles/hour

#### Force

1 pound = 16 ounces = 4.45 newtons
1 newton = 0.223 pounds

#### Temperature

32F = 0C = 273 Kelvin

#### Pressure

Air pressure at sea level = 1.01 X 10^5 newtons/square meter = 14.7 pounds/square

#### Heat and Work Energy

1 calorie = 4.18 joules = 0.00442 Btu

#### Power

1 horsepower = 550 foot pounds/second = 746 watts
1 watt = 1 joule/second = 0.239 calorie/second = 3.80 Btu/hour
1 kilowatt = 1.34 horsepower

#### Metric Prefixes

 T Tera 10^12 1,000,000,000,000 G Giga 10^9 1,000,000,000 M Mega 10^6 1,000,000 k Kilo 10^3 1000 h Hecto 10^2 100 da Deka 10^1 10 d Deci 10^-1 0.1 c Centi 10^-2 0.01 m Milli 10^-3 0.001 u Micro 10^-6 0.000,001 n Nano 10^-9 0.000,000,001 p Pico 10^-12 0.000,000,000,001