3

Conversion of Units

Base SI Units

Derived SI Units

Quantity Derived SI Unit Name Symbol

area meter2 m² volume meter3 m³ density kilogram / meter3 kgm/m³ force kilogram-meter / second2 newton N

moment of force newton-meter N-m pressure newton / meter2 pascal Pa

stress newton / meter2 pascal Pa or N/m² work, energy newton-meter joule J

power joule / second watt W

Multiplication Factor Prefix SI Symbol

1 000 000 000 giga G

1 000 000 mega M

1 000 kilo k

0.001 milli m

0.000 001 micro µ

0.000 000 001 nano n

Quantity Unit Symbol

length meter m mass kilograms mass kgm force newton N

time second s

4

Conversion of SI Units to English Units

Lengths Multiply by To

From inches feet yards miles

mm 3.94 x 10-2 3.28 x 10-3 1.09 x 10-3 6.22 x 10-7

cm 3.94 x 10-1 3.28 x 10--2 1.09 x 10-2 6.22 x 10-6

m 3.94 x 101 3.28 1.09 6.22 x 10-4

km 3.94 x 104 3.28 x 103 1.09 x 103 6.22 x 10-1

Area Multiply by To

From square inches square feet square yards square miles

mm² 1.55 x 10-3 1.08 x 10-5 1.20 x 10-6 3.86 x 10-13

cm² 1.55 x 10-1 1.08 x 10-3 1.20 x 10-4 3.86 x 10-11

m² 1.55 x 103 1.08 x 101 1.20 3.86 x 10-7

km² 1.55 x 109 1.08 x 107 1.20 x 106 3.86 x 10-1

Volume Multiply by To

From cubic inches cubic feet cubic yards quarts gallons

cm3 6.10 x 10-2 3.53 x 10-5 1.31 x 10-6 1.06 x 10-3 2.64 x 10-4

liter 6.10 x 101 3.53 x 10-2 1.31 x 10-3 1.06 2.64 x 10-1

m³ 6.10 x 104 3.53 x 101 1.31 1.06 x 103 2.64 x 102

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Force Multiply by To

From ounces pounds kips tons (short)

dynes 1.405 x 10-7 2.248 x 10-6 2.248 x 10-9 1.124 x 10-9

grams 3.527 x 10-2 2.205 x 10-3 2.205 x 10-6 1.102 x 10-6

kilograms 3.527 x 101 2.205 2.205 x 10-3 1.102 x 10-3

newtons 3.597 2.248 x 10-1 2.248 x 10-4 1.124 x 10-4

kilo-newtons 3.597 x 103 2.248 x 102 2.248 x 10-1 1.124 x 10-1

tons (metric) 3.527 x 104 2.205 x 103 2.205 1.102

Pressure (stress) � Multiply by To

From lb/in² lb/ft² kips/ft² tons (short)/ft² feet of water atmosphere

gm/cm² 1.422 x 10-2 2.048 2.048 x 10-3 1.024 x 10-3 3.281 x 10-2 9.678 x 10-4

kg/cm² 1.422 x 101 2.048 x 103 2.048 1.024 3.281 x 101 9.678 x 10-1

kN / m² 1.450 x 10-1 2.090 x 101 2.088 x 10-2 1.044 x 10-2 3.346 x 10-1 9.869 x 10-3

ton (metric)/m² 1.422 2.048 x 102 2.048 x 10-1 1.024 x 10-1 3.281 9.678 x 10-2

Torque ( moment) T or M Multiply by To

From lb-in² lb-ft kips-ft

gm-cm 8.677 x 10-8 7.233 x 10-5 7.233 x 10-8

kg-m 8.677 7.233 7.233 x 10-3

kN-m 9.195 x 103 7.663 x 102 7.663 x 10-1

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Velocity v Multiply by To

From ft / s ft / min mi / h cm / s 3.281 x 10-2 1.9685 2.236 x 10-2

km / min 5.467 x 101 3.281 x 103 3.728 x 101 km / h 9.116 x 10-1 5.467 x 101 6.214 x 10-1

1 mile = 1,610 meters = 5,282.152 feet

Unit weight � Multiply by To

From lb / in³ lb / ft³ gm / cm³ 3.613 x 10-2 6.248 x 101 kg / m³ 3.613 x 10-5 6.248 x 10-2 kN / m³ 3.685 x 10-3 6.368 x 101

tons (metric ) / m³ 3.613 x 10-2 6.428 x 101