POWER
1 W = 0.737 ft-lbf/s
1 W = 1 N-m/s
1 W = 1 J/s
1 W = 3.412 BTU/hr
1 W = 0.0013 hp (Britist)
1 kW = 1.34 hp
1 kW = 1.36 PS (SAE)
1 kW = 1.47 PS (JIS)
1 hp = 746 W
1 hp = 0.7457 kW
1 hp = 1.0139 hp (Metric)
1 hp (SAE) = 1.014 PS (DIN)
1 hp (Metric) = 735.499 W
1 hp (British) = 745.699 W
1 hp (British) = 1.01387 hp (metric)
1 hp (British) = 2544 Btu /hr
1 hp (British) = 0.212 ton (refrigeration)
1 hp (Boiler) = 13.1548 hp (British)
1 hp (Boiler) = 13.3337 hp (metric)
1 hp (DIN) = 0.735 kW
1 hp (DIN) = 0.735 hp (SAE)

Pressure
1 atm (Atmospheres)  = 101325 Pa = 101325 kg/ m· s² = 101325 N/ m²
1 atm (Atmospheres) = 1013.25 hPa = 1013.25 mbar
1 atm (Atmospheres) = 101.325 kPa
1 atm (Atmospheres) = 1.01325 bar<!--PAR-->
1 atm (Atmospheres) = 14.696 lb/in²
1 atm (Atmospheres) = 1.033 kg/cm²
1 atm (Atmospheres) = 1.013 bar
1 kg/cm2 = 14.223 lb/in²
1 kg/cm2 = 0.981 bar
1 kg/cm2 = 98.1 kN/m²
1 kg/cm2 = 98.1 kPa
1 N/m2 =0.000145 lbf/in²
1 lbf/in2 = 6.895 kN/m²
1 lbf/in2 = 0.068947 bar
1 lbf/in2 = 0.070 kg/cm²
1 lbf/in2 = 0.068 atm (Atmospheres)
1 lbf/in2 = 2.0416 in of Hg
1 lbf/in2 = 27.71 in of Water
1 bar = 0.9869 atm (Atmospheres)
1 bar = 14.5038 lbf/in²
1 bar = 1.02 kg/cm²
1 bar = 29.527 in of Hg
1 bar = 33.8 ft of Water
1 bar = 42 ft of Oil
1 bar = 10⁵ N/m²
1 bar = 10⁵ Pa
1 Pa = 1 N/m²
1 kPa = 0.01 kgf/cm²
1 MPa = 10 kgf/cm²
1 in of Hg = 0.491 lb/in²
1 in of Hg = 1.132 ft of Water
1 in of Hg = 25.4 mm of Hg
1 ft of Water = 0.433 lb/in²
1 ft of Oil = 0.4 lb/in²

Torque
1 N-m = 0.738 lbf-ft
1 N-m = 8.8507 lbf-in
1 N-m = 0.102 kgf-m
1 lbf-ft = 0.1382 kgf-m
1 lbf-ft = 1.356 N-m
1 lbf-ft = 0.1129 N-m
1 lbf-ft = 0.0115 kgf-m
1 kgf-m = 86.795 lbf/in
1 kgf-m = 7.233 lbf-ft
1 kgf-m = 9.81 N-m

Speed
1 in/s = 0.083 ft/s
1 m/s = 3.281 ft/s
1 m/s = 60 m/min
1 ft/s = 0.035 m/s
1 ft/s = 12 in/s
1 ft/min = 0.2 in/s
1 km/h = 0.621 mph
1 kph = 1.61 km/h

Volume
1 in3 = 16.387 cm³
1 in3 = 16.387 ml
1 in3 = 16.387 cc
1 ft3 = 1728 in³
1 ft3 = 7.48 Gallon
1 ft3 = 0.0283 m³
1 ft3 = 28.32 Litre
1 cm3 = 0.001 Litre
1 cm3 = 1000 mm³
1 cc = 0.001 Litre
1 ml = 0.001 Litre
1 m3 = 1000 dm³
1 m3 = 35.3 ft³
1 m3 = 1000 Litre
1 dm3 = 1000 cm³
1 U.S. Gallon = 231 in3
1 U.S. Gallon = 3.785 Litre
1 IMP Gallon = 277.4 in3
1 IMP Gallon = 4.546 Litre
1 IMP Gallon = 1.2 U.S. Gallon
1 Litre = 1000 cm³
1 Litre = 1000 cc
1 Litre = 0.001 m³
1 Litre = 0.2642 U.S. Gallon
1 Litre = 0.22 IMP Gallon
1 ml = 0.061 in³
1 cm3 = 0.061 in³
10 ml = 0.61024 in³
10 cm3 = 0.61024 in³
1 Barrel (Oil) = 42 Gallon
1 Barrel (Oil) = 158.99 Litre
1 cu.ft = 1728 cu.in

Temperature
C = 5/9 (F-32)
F = 32 + (C x 9/5)
R = F + 459.67
K = C + 273.15

Prefix
Tera = 1,000,000,000,000
Giga = 1,000,000,000
Mega = 1,000,000
Kilo = 1,000
Hecto = 100
Deka = 10
Deci = 0.1
Centi = 0.01
Milli = 0.001
Micro = 0.000001
Nano = 0.000000001
Pico = 0.000000000001
Femto = 0.000000000000001
Atto = 0.000000000000000001

Area
1 mm² = 0.002 in²
100 mm² = 1.55 in²
1 m² = 100 dm²
1 m² = 10000 cm²
100 m² = 10.764 in²
1 dm² = 100 cm²
1 dm² = 10000 mm²
1 in² = 645.16 mm²
1 in² = 6.452 cm²
1 ft² = 0.093 m²
1 Acres = 4046.85 m²

Length
1 ไมโครm = 0.000001 m
1 ไมโครm = 0.001 mm
1 ไมโครm = 0.000039 in
25 ไมโครm = 0.001 in
1 nm = 0.000001 mm
1 mm = 1000 ไมโครm
1 mm = 0.039 in
1 cm = 10 mm
1 m = 10 dm
1 m = 100 cm
1 m = 3.28 ft
1 m = 39.37 in
1 dm = 10 cm
1 ft = 0.3048 m
1 ft = 30.48 cm
1 in = 25.4 mm
1 in = 2.54 cm
1 km = 1000 m
1 km = 0.621 mile
1 mile = 1.609 km

Mass

1 kg = 2.205 lb
1 kg = 9.81 N
1 kg = 1000 g
1 lb = 0.454 kg
1 N = 0.2248 lb
1 N = 0.102 kg
1 kN = 0.1004 ton
1 ton = 2204 ib
1 ton = 1000 kg
1 ton = 9.964 kN
1 carat = 0.2 g
1 carat = 200 mg

  Time

1 min = 60 s
1 hr = 60 min
1 hr = 3600 s

Acceleration

1 m/s² = 3.281 ft/s²
1 ft/s² = 0.305 m/s²

Energy , Work
1 J = 0.738 ft-lbf
1 J = 1 N-m
1 J = 1 Ws
1 J = 0.239 calorie
1 ft-lbf = 1.3558 J
1 calorie = 4.186 J
1 kJ = 0.9478 Btu
1 Btu = 1054.3 J
1 Btu = 1.05506 kJ
1 Btu = 252.16 calorie
1 Btu = 0.00029 kWh
1 Btu = 0.000392 hp-hr (British)
1 Btu = 0.000398 hp-hr (Metric)
1 kJ = 0.526 CHU
1 CHU = 1.9 kJ

Specific fuel consumption
1 kg/kWh = 1.645 lb/bhp h
1 lb/bhp h = 0.6088 kg/kWh
1 litre/kWh = 1.316 pt/bhp h
1 pt/bhp h = 0.76 litre/kWh
1 km/litre = 2.366 mile/Gallon
1 mile/Gallon = 0.423 km/litre

Calorific value
1 kJ/kg = 0.4303 Btu/lb
1 Btu/lb = 2.324 kJ/kg
1 kJ/kg = 0.239 CHU/lb
1 CHU/lb = 4.1868 kJ/kg

ความเร็วแสงในสุญญากาศ 2.997925 x 100000000 m/s
ความเร็วเสียงที่ระดับน้ำทะเล 340.3 m/s
อัตราเร่งจากแรงโน้มถ่วง (g) 9.80665 m/s²
ความหนาแน่นของโลก 5522 kg/m²
เส้นผ่าศูนย์กลางโลก 12760 km