Basic Mathematical Formulas
Distance
1 foot = 12 inches
1 yard = 3 feet
1 mile = 5,280 feet
1 mile ≈ 1.61 kilometers
1 inch = 2.54 centimeters
1 foot = 0.3048 meters
1 meter = 1,000 millimeters
1 meter = 100 centimeters
1 kilometer = 1,000 meters
1 kilometer ≈ 0.62 miles
Area
1 square foot = 144 square inches
1 square yard = 9 square feet
1 acre = 43,560 square feet
Volume
1 cup = 8 fluid ounces
1 quart = 4 cups
1 gallon = 4 quarts
1 gallon = 231 cubic inches
1 liter ≈ 0.264 gallons
1 cubic foot = 1,728 cubic inches
1 cubic yard = 27 cubic feet
1 board foot = 1 inch by 12 inches by 12 inches
Weight
1 ounce ≈ 28.350 grams
1 pound = 16 ounces
1 pound ≈ 453.592 grams
1 milligram = 0.001 grams
1 kilogram = 1,000 grams
1 kilogram ≈ 2.2 pounds
1 ton = 2,000 pounds
Rectangle
perimeter = 2(length + width)
area = length x width
Rectangular Solid (Box)
volume = length x width x height
Cube
volume = (length of side)3
Triangle
sum of angles = 180°
area = ½ (base x height)
Circle
number of degrees in a circle = 360°
circumference ≈ 3.14 x diameter
area ≈ 3.14 x (radius)2
Cylinder
volume ≈ 3.14 x (radius)2 x height
Cone
volume ≈ 
Sphere (Ball)
volume ≈ 4/3 x 3.14 x (radius)3
Electricity
1 kilowatt-hour = 1,000 watt-hours
amps = watts ÷ volts
Temperature
°C = 0.56(°F – 32) or 5/9(°F – 32)
°F = 1.8(°C) + 32 or ( 9/5 x °C) + 32