### Common units

Kilometer (km), meter (m), centimeter (cm), millimeter (mm), mile (mi), feet (ft), inch (in)

1 km = 1,000 m = 0.62 mi

1 m = 100 cm = 1,000 mm = 3.28 ft = 39.37 in

1 in = 25.4 mm

1 mi = 5,280 ft

1 km = 1,000 m = 0.62 mi

1 m = 100 cm = 1,000 mm = 3.28 ft = 39.37 in

1 in = 25.4 mm

1 mi = 5,280 ft

Square meter (m²), square feet (ft²)

1 m² = 10.76 ft²

10 ft² = 0.93 m²

1 m² = 10.76 ft²

10 ft² = 0.93 m²

Cubic meter (m³), liter (L), milliliter (mL), cubic centimeter (cc), gallon (gal), quart (qt), pint (pt), ounce (fl oz), cubic feet (ft³)

1 m³ = 1,000L = 264.2gal

1 L = 1,000mL = 1,000cc = 0.2642gal

1 gal = 4qt = 8pt = 128fl oz = 0.134ft³ = 3.785L

1 ft³ = 7.48gal = 28.3L

1 m³ = 1,000L = 264.2gal

1 L = 1,000mL = 1,000cc = 0.2642gal

1 gal = 4qt = 8pt = 128fl oz = 0.134ft³ = 3.785L

1 ft³ = 7.48gal = 28.3L

Metric ton (t), kilogram (kg), gram (g), ton (tn), pound (lb), ounce (oz)

1 t = 1,000 kg = 1.1 tn

1 kg = 1,000 g = 2.2 lb

1 tn = 2,000 lb

1 lb = 16 oz

1 t = 1,000 kg = 1.1 tn

1 kg = 1,000 g = 2.2 lb

1 tn = 2,000 lb

1 lb = 16 oz

Celsius (°C), kelvin (K), fahrenheit (°F)

°F = °C × 9/5 + 32

K = °C + 293.15

°F = °C × 9/5 + 32

K = °C + 293.15

kilogram / cubic meter (kg/m³), g / cubic centimeter (g/cm³), pound / cubic feet (lb/ft³), pound / gallon (lb/gal)

1,000kg/m³ = 1g/cm³ = 62.43lb/ft³ = 8.35lb/gal

1,000kg/m³ = 1g/cm³ = 62.43lb/ft³ = 8.35lb/gal

Specific gravity (S.G.) is ratio of density between specific matter and water. So, specific gravity is dimensionless

Kilometer / hour (km/hr), meter / minute (m/min), meter / second (m/s), mile / hour (mi/hr), foot / minute (ft/min), foot / second (ft/s)

3.6km/hr = 60m/min = 1m/s = 3.28ft/s

0.68mi/hr = 60ft/min = 1ft/s

3.6km/hr = 60m/min = 1m/s = 3.28ft/s

0.68mi/hr = 60ft/min = 1ft/s

Cubic meter / hour (m³/hr), liter / minute (Lpm), liter / second (L/s), Cubic meter / second (m³/s), gallon / minute (gpm)

3.6 m³/hr = 60 Lpm = 0.001 m³/s = 1L/s = 15.85 gpm

1 gpm = 0.063 L/s = 3.785 L/min = 0.227 m³/hr

3.6 m³/hr = 60 Lpm = 0.001 m³/s = 1L/s = 15.85 gpm

1 gpm = 0.063 L/s = 3.785 L/min = 0.227 m³/hr

Newton (N), kilonewton (kN), pound force (lbf)

1 kN = 1,000 N = 224.8 lbf

1 kN = 1,000 N = 224.8 lbf

Kilowatt hour (kW·h), joule (J), British thermal unit (BTU), calorie (cal)

1 kW·h = 3,600,000 J = 3,412.14 BTU = 859.85 cal

1 kW·h = 3,600,000 J = 3,412.14 BTU = 859.85 cal

Kilowatt (kW), watt (W), horse power (hp)

0.746 kW = 746 W = 1 hp

0.746 kW = 746 W = 1 hp

Newton meter (N·m), pound force foot (lbf·ft)

1 N·m = 0.74 lbf·ft

1 lbf·ft = 1.36 N·m

1 N·m = 0.74 lbf·ft

1 lbf·ft = 1.36 N·m

Revolution / minute (rpm), revolution / second (rev/s) radian / second (rad/s)

60 rpm = 1 rev/s = 6.28 rad/s

60 rpm = 1 rev/s = 6.28 rad/s

Pascal (Pa), kilopascal (kPa), megapascal (MPa), bar, kilogram / square centimeter (kgf/cm²), atmosphere (atm), pound / square inch (psi)

1 MPa = 1,000 kPa = 1,000,000 Pa = 10 bar = 10.2 kgf/cm² = 145 psi

1 atm = 1.0133 bar = 14.7 psi

1 MPa = 1,000 kPa = 1,000,000 Pa = 10 bar = 10.2 kgf/cm² = 145 psi

1 atm = 1.0133 bar = 14.7 psi

Kilogram meter square (kg·m²), gram centimeter square (g·cm²), pound foot square (lb·ft²)

1 kg·m² = 10,000,000 g·cm² = 23.73 lb·ft²

1 kg·m² = 10,000,000 g·cm² = 23.73 lb·ft²

Concentration units are classified as 4 main types

- Volume against volume (v/v) - percentage (%), part per thousand (ppt), part per million (ppm)

- Mass against mass (w/w) - percentage (%), part per thousand (ppt), part per million (ppm)

- Mass against volume (w/v) - kilogram / cubic meter (kg/m³), gram / 100 milliliter (g/100mL); 1 kg/m³ = 0.1 g/100mL

- Molar concentration (Molarity) - Mole / liter (c or mol/L); 1 c = 1 mol/L

These 4 types of concentration units are only interchangeable under certain condition

- Volume against volume (v/v) - percentage (%), part per thousand (ppt), part per million (ppm)

- Mass against mass (w/w) - percentage (%), part per thousand (ppt), part per million (ppm)

- Mass against volume (w/v) - kilogram / cubic meter (kg/m³), gram / 100 milliliter (g/100mL); 1 kg/m³ = 0.1 g/100mL

- Molar concentration (Molarity) - Mole / liter (c or mol/L); 1 c = 1 mol/L

These 4 types of concentration units are only interchangeable under certain condition

N·s/m², Pa·s, mPa·s, poise (P), centipoise (cP, cp, cPs)

1 N·s/m² = 1 Pa·s = 1,000 Pa·s = 10 P = 1,000 cP

1 N·s/m² = 1 Pa·s = 1,000 Pa·s = 10 P = 1,000 cP

m²/s, mm²/s, stoke (St), centistoke (cSt)

0.0001 m²/s = 100 mm²/s = 1 St = 100 cSt

0.0001 m²/s = 100 mm²/s = 1 St = 100 cSt

Kinematic viscosity (m²/s) = Dynamic viscosity (N·s/m²) / Density (kg/m³)

There are many other viscosity units, such as SSU, SUS, SSF.

However, most of them replaced by either dynamic viscosity units or kinematic viscosity units as their conversion are usually under limitations.

However, most of them replaced by either dynamic viscosity units or kinematic viscosity units as their conversion are usually under limitations.