Conversion Factors

Table 1 The relationship between English and SI (metric) length units Both four and eight digits are given for each relationship. Four digits are usually adequate for English‑SI conversions.

Metric	English	English	Metric
kilometer (km)	0.6214 mi 0.62137119 mi	mile (mi)	1.609 km 1.609344 km (exact)
	3281 ft 3280.8399 ft		1609 m 1609.344 m (exact)
meter (m)	3.281 ft 3.2808399 ft
	39.37 in. 39.370079 in.	yard (yd)	0.9144 m (exact)
	1.094 yd 1.0936133 yd		91.44 cm (exact)
centimeter (cm)	0.3937 in. 0.39370079 in.
	0.03281 ft 0.032808399 ft	foot (ft)	30.48 cm (exact)
millimeter (mm)	3.937 x 10^-2 in. 3.9370079 x 10^-² in.		0.3048 m (exact)
micrometer (mm)	3.937 x 10^-⁵ in. 3.9370079 x 10^-⁵ in.
nanometer (nm)	3.937 x 10^-⁸ in. 3.9370079 x 10^-⁸ in.	inch (in.)	2.54 cm (exact)
			0.0254 m (exact)

Table 2 The relationship between English mass units and SI (metric) mass units Both four and eight digits are given for each relationship. Four digits are usually adequate.

Metric Mass	English Mass	English Mass	Metric Mass
metric ton (ton)	1.102 ton (short) 1.1023113 ton (short)	ton (ton)	0.9072 metric tons 0.90718474 metric tons
	2205 lb 2204.6226 lb		907.2 kg 907.18474 kg
kilogram (kg)	2.205 lb 2.2046226 lb
	0.001102 ton 0.0011023113 ton	pound (lb)	453.6 g 453.59237 g
gram (g)	0.002205 lb 0.0022046226 lb		0.4536 kg 0.45359237 kg
	0.03527 oz 0.035273962 oz
milligram (mg)	3.527 x 10^-⁵ oz 3.5273962 x 10^-⁵ oz	ounce (oz)	28.35 g 28.349523 g
microgram (mg)	3.527 x 10^-⁸ oz 3.5273962 x 10^-⁸ oz		2.835 x 10⁴ mg 2.8349523 x 10⁴ mg

Table 3 The relationship between English and SI (metric) volume units Both four and seven digits are given for each relationship. Four digits are usually adequate.

Metric	English	English	Metric
liter (L)	1.057 qt 1.056718 qt	gallon * (gal)	3.785 L 3.785306 L
	0.2642 gal 0.2641795 gal		3785 mL 3785.306 mL
	33.81 fl oz 33.81498 fl oz	quart * (qt)	0.9463 L 0.9463264 L
	61.03 cu in. 61.02545 cu in.		946.3 mL 946.3264 mL
milliliter (mL)	0.03381 fl oz 0.03381497 fl oz	fluid ounce * (fl oz)	0.02957 L 0.02957270 L
	0.06103 cu in. 0.06102545 cu in.		29.57 mL 29.57270 mL
microliter (mL)	3.381 x 10^-⁵ fl oz 3.381497 x 10^-⁵ fl oz	cubic inch (cu in.)	16.39 cm³ 16.387064 cm³ (exact)
cubic centimeter (cm³)	0.03381 fl oz 0.03381497 fl oz		16.39 mL 16.387064 mL (exact)
	0.06103 cu in. 0.06102545 cu in.		0.1634 L 0.16387064 L (exact)

* There are three kinds of gallons, quarts, and fluid ounces: British, U.S. dry, and U.S. liquid. The values given here are for U.S. liquid gallons, quarts, and fluid ounces.