You can use this chart to convert imperial (US) units to metric units. Multiply the imperial value by the conversion factor to get the metric value.

(Imperial Units) X (Conversion Factor) = Metric Units

CONVERSION FACTORS TO CONVERT FROM IMPERIAL TO METRIC
QUANTITYFROM INCH-POUND UNITSTO METRIC UNITSMULTIPLY BY
Lengthmilekm1.609344
yardm0.9144
footm0.3048
mm304.8
inchmm25.4
Areasquare milekm22.59
acrem24046.87
ha (10000m2)0.404687
square yardm20.83612736
square footm20.09290304
square inchmm2645.16
Volumeacre footm31233.49
cubic yardm30.764555
cubic footm30.0283168
cm328316.85
L (1000 cm3)28.31685
100 board feetm30.235974
gallonL (1000 cm3)3.78541
cubic inchcm316.387064
mm316387.064
ADDITIONAL CONVERSION FACTORS
QUANTITYFROM INCH-POUND UNITSTO METRIC UNITSMULTIPLY BY
Masslbkg0.453592
Kip (1000 lb)metric ton (1000 kg)0.453592
Mass/unit lengthplfkg/m1.48816
Mass/unit areapsfkg/m24.88243
Mass densitypcfkg/m316.0185
ForcelbN4.44822
Force/unit lengthplfN/m14.5939
Pressure, stress, modulus of elasticitypsfPa47.8803
psikPa6.89476
bending moment, torque, moment of forceft-lbNm1.35582
moment of masslb ftkg m0.138255
moment of inertialb ft2kg m20.0421401
second moment of inertiain4mm4416231
second modulusin3mm316387.064
mass/area (density)lb/ft2kg/m24.882428
temperature˚F˚C5/9 ˚F-32
energy, work, quantity of heatkWhMJ 3.6
BtuJ1055.056
ft lbfJ1.35582
Powerton (refrig)Kw3.517
Btu/skW1.055056
hp (electric)W745.7
Btu/hW0.293071
Heat fluxBtu/f2hW/m3.152481
Rate of heat flowBtu/skW1.055056
Btu/hw0.2930711
Thermal conductivuty ( k value)Btu/ ft h ˚FW/m K1.73073
Thermal conductance (U value)Btu ft2 h ˚FW/m2 K5.678263
Thermal resistance (R value)ft2 h ˚F/Btum2 K/W0.17611
Heat capacity, entrophyBtu/ ft h ˚FkJ/K1.8991
Specific heat capacity, specific entrophyBtu/ lb ˚FkJ/kg K4.1868
specific energy, latent heatBtu/lbKJ/kg2.326
vapor permeanceperm (23 ˚C )ng/ (Pa s m2)57.4525
Vapor permeabilityperm/inng/ (Pa s m2)1.45929
Volume rate of flowft3/sm3/s0.0283168
cfmm3/s0.0004719474
cfmL/s0.4719474
Velocity, speedft/sm/s0.3048
Accelerationft/s2m/s20.3048
Momentumlb ft/skg m/s0.138255
Angular momentumlb ft2/skg m2/s0.04214011
Plane angledegreerad0.0174533
Power, radiant fluxWW1 (same unit)
Radiant intensityW/srW/sr1 (same unit)
RadianceW/ (sr m2)W/ (sr m2)1 (same unit)
IrradianceW/ m2W/ m21 (same unit)
FrequencyHzHz1 (same unit)
Electric currentAA1 (same unit)
Electric chargeA hrC3600
Electric potentialV V1 (same unit)
CapacitanceFF1 (same unit)
InductanceHH1 (same unit)
ResistanceWW1 (same unit)
ConductancemhoS100
Magnetic fluxmaxwellWb10-8
Magnetic flux densitygammaT10-9
Luminous intensitycdcd1 (same unit)
Luminancelambertkcd/m23.18301
cd/ft2cd/m210.7639
foorlambertcd/m23.42626
Luminous fluxlmlm1 (same unit)
Illuminancefootcandlelx10.7639

Source: Architectural Graphic Standards