Conversion Factors and Formulas

Length

If working with feet, inches and fractions or a combination of these, express the length in inches before converting. Use a calculator or consult our Fraction-to-Decimal Conversion Charts if necessary, to get decimal equivalents for fractions.

Example: Convert 5 feet, 5 and three-quarter inches to meters.

Convert feet to inches: 5 × 12 = 60 inches
Express three-quarters as a decimal: .75
Add values together: 60 + 5 + .75 = 65.75 inches

Now convert to meters:
One inch equals .0254 meter, so multiply.
65.75 × .0254 = 1.67005 (round off to hundredths: 1.67 meters).

One meter equals
39.37 inches
3.2808 feet
1.0936 yards
One centimeter equals
.3937 inch
One millimeter equals
.03937 inch
One kilometer equals
3280.84 feet
1093.61 yards
.62137 mile
.53996 nautical mile
One nautical mile equals
1.852 kilometers
1852 meters
6076.115 feet
2025.372 yards
1.15078 miles
One inch equals
.0254 meter
2.54 centimeters
25.4 millimeters
One foot equals
.3048 meter
30.48 centimeters
304.8 millimeters
12 inches
One yard equals
.9144 meter
91.44 centimeters
914.4 millimeters
36 inches
3 feet
One mile equals
1.609344 kilometers
1609.344 meters
5280 feet
1760 yards
.868976 nautical mile

Mass or Weight

If working with pounds, ounces and fractions or a combination of these, express the value in ounces before converting.

Example: Convert 7 pounds, 9 and a half ounces to kilograms.

Convert pounds to ounces: 7 × 16 = 112
Express the half as a decimal: .5
Add values together: 112 + 9 + .5 = 121.5

Now convert to kilograms:
One ounce equals .02835 kilograms, so multiply.
121.5 × .02835 = 3.444525 (round off to hundredths: 3.44 kilograms).

One metric ton equals
1.10229 U.S. tons
2204.59 pounds
One kilogram equals
2.2046 pounds
35.273 ounces
One gram equals
.035273 ounce
15.432 grains
One U.S. ton equals
907.2 kilograms
.9072 metric tons
2000 pounds
One pound equals
453.6 grams
.4536 kilograms
16 ounces
7000 grains
One ounce equals
28.35 grams
.02835 kilograms
437.5 grains
One grain equals
64.8 milligrams

Temperature

To convert Celsius to Fahrenheit, multiply by 1.8, then add 32.

Example: 10 °C
10 × 1.8 = 18
18 + 32 = 50 °F

To convert Fahrenheit to Celsius, subtract 32, then divide by 1.8.
Example: 77 °F
77 - 32 = 45
45 ÷ 1.8 = 25 °C

Velocity

One meter per second equals
3.6 kilometers per hour
2.2369 miles per hour
1.9438 knots
3.2808 feet per second
One kilometer per hour equals
.27778 meters per second
.62137 miles per hour
.53996 knots
.91134 feet per second
One kilometer per second equals
3600 kilometers per hour
2236.94 miles per hour
1943.84 knots
3280.84 feet per second
.62137 miles per second
One mile per hour equals
.44704 meters per second
1.6093 kilometers per hour
.86898 knots
1.4667 feet per second
One knot equals
.51444 meters per second
1.852 kilometers per hour
1.1508 miles per hour
1.6878 feet per second
One foot per second equals
.3048 meters per second
1.09728 kilometers per hour
.68182 miles per hour
.59248 knots
One mile per second equals
1609.344 meters per second
5793.6384 kilometers per hour
3600 miles per hour
3128.31 knots
5280 feet per second

Pressure

One kilopascal equals
.2953 inches of mercury
7.5006 millimeters of mercury
.14504 pounds per square inch
One hectopascal (used in U.S. aviation weather reports) equals
.1 kilopascal or 100 pascals
One inch of mercury equals
3.38638 kilopascals
25.4 millimeters of mercury
.49115 pound per square inch
One millimeter of mercury equals
.133322 kilopascal
133.322 pascals
.03937 inch of mercury
.019337 pound per square inch
One pound per square inch equals
6.894757 kilopascals
2.036 inches of mercury
51.715 millimeters of mercury

Area

To calculate area from dimensions:

  1. Be sure both dimensions are in the same units (meters or whatever).
  2. Multiply length times width to get square units.
  3. Convert square units if desired.

Example: A room measures 13 by 15 feet. Calculate the area in square meters.

13 feet × 15 feet = 195 square feet.
One square foot equals .0929 square meter, so multiply by .0929.
195 × .0929 = 18.1155 square meters.
Tenths of a square meter is probably sufficient. Round off to 18.1.

One square meter equals
1550 square inches
10.7639 square feet
1.19599 square yards
One square centimeter equals
.155 square inch
One square millimeter equals
.00155 square inch
One hectare equals
107639.1 square feet
11959.9 square yards
2.471 acres
.003861 square mile
.0029155 square nautical mile
One square kilometer equals
247.105 acres
.3861 square mile
.29155 square nautical mile
One square inch equals
6.4516 square centimeters
645.16 square millimeters
One square foot equals
.0929 square meter
929.03 square centimeters
144 square inches
One square yard equals
.83613 square meter
1296 square inches
9 square feet
One acre equals
4046.86 square meters
.4047 hectare
.004047 square kilometers
43560 square feet
4840 square yards
.0015625 square mile
.0011799 square nautical mile
One square mile equals
258.9988 hectares
2.59 square kilometers
640 acres
.75512 square nautical mile
One square nautical mile equals
342.9904 hectares
3.4299 square kilometers
847.55 acres
1.3243 square miles

Capacity or Volume

To calculate capacity or volume from dimensions:

  1. Be sure all dimensions are in the same units (meters or whatever).
  2. Multiply length times width times height to get cubic units.
  3. Convert cubic units if desired.

Example: A refrigerator is 60 inches high, 24 inches wide and 18 inches deep (interior dimensions). Calculate the capacity in cubic feet.

60 inches × 24 inches × 18 inches = 25920 cubic inches.
One cubic foot equals 1728 cubic inches, so divide by 1728.
25920 ÷ 1728 = 15 cubic feet capacity.

One fluid ounce equals
29.5735 milliliters
6 teaspoons
2 tablespoons
.125 cup
1.8047 cubic inches
One liquid cup equals
236.588 milliliters
48 teaspoons
16 tablespoons
8 fluid ounces
.5 pint
.25 quart
14.4375 cubic inches
One liquid pint equals
.47318 liter
473.176 milliliters
96 teaspoons
32 tablespoons
16 fluid ounces
2 cups
.5 quart
.125 gallon
28.875 cubic inches
One liter equals
202.88 teaspoons
67.628 tablespoons
33.814 fluid ounces
4.2268 cups
2.1134 pints
1.0567 quarts
.26417 gallon
.11377 peck
61.0237 cubic inches
One milliliter equals
.20288 teaspoon
One cubic meter equals
264.172 gallons
113.765 pecks
28.4413 bushels
35.3147 cubic feet
1.30795 cubic yards
One teaspoon equals
4.9289 milliliters
.30078 cubic inch
One tablespoon equals
14.7868 milliliters
3 teaspoons
.5 fluid ounce
.90234 cubic inch
One liquid quart equals
.94635 liter
946.353 milliliters
192 teaspoons
64 tablespoons
32 fluid ounces
4 cups
2 pints
.25 gallon
57.75 cubic inches
One liquid gallon equals
3.7854 liters
768 teaspoons
256 tablespoons
128 fluid ounces
16 cups
8 pints
4 quarts
231 cubic inches
One dry peck equals
8.79 liters
.25 bushel
536.4 cubic inches
One dry bushel equals
35.16 liters
4 pecks
2145.6 cubic inches
1.2417 cubic feet
One cubic inch equals
16.3871 milliliters
3.3247 teaspoons
1.1082 tablespoons
.55411 fluid ounce
One cubic foot equals
28.3168 liters
7.48052 gallons
3.22148 pecks
.80537 bushel
1728 cubic inches
One cubic yard equals
764.555 liters
.76455 cubic meter
201.974 gallons
86.98 pecks
21.745 bushels
27 cubic feet

Density

One gram per cubic centimeter equals
1000 kilograms per cubic meter
62.4269 pounds per cubic foot
998.83 ounces per cubic foot
One pound per cubic foot equals
16.0187 kilograms per cubic meter
One ounce per cubic foot equals
1.00117 kilograms per cubic meter