Common Length Unit Conversions

1 meter = 3.281 feet

1 mile = 5,280 feet

1 mile = 1,609 meters

1 foot = 12 inches

1 inch = 2.540 cm

1 yard = 91.44 cm

1 light year (ly) = 9.461 * 10¹⁵ m

Common Time Unit Conversions

1 min = 60 s

1 hour = 60 min

1 day = 24 hours

1 week = 7 days

1 fortnight = 2 weeks

1 year = 365.24 days

1 century = 100 years

Common Mass Unit Conversions

1 kg = 1000 g

1 kg = 2.205 lbs on Earth’s surface

1 amu = 1.661 * 10^-27 kg

1 oz = 0.0625 lbs

Common Volume Unit Conversions

1 liter = 10^-3 m³

1 gallon = 3.788 liters

1 fl oz = 29.57 ml

1000 ml = 1 liter

Common Force Unit Conversions 

1 N = 0.2248 lbs on Earth’s surface

1 N = 10⁵ dyne

Common Energy Unit Conversions

1 Joule = 10⁷ ergs

1 cal = 4.186 J

1 Btu = 1055 J

1 eV = 1.602 * 10^-19 J

1 kWh = 3.600 * 10⁶ J

Common Angular Unit Conversions

1 radian (rad)  = 57.30 degrees

1 rad = 180/pi degrees

1 rev = 2 * pi rad

Common Power Unit Conversions

1 W = 1 J/s

1 hp = 746 W

1 Btu/h = 0.293 W

Common Pressure Unit Conversions

1 Pa = 1 N/m²

1 Pa = 1.450 * 10^-4 lb/in²

1 bar = 10⁵ Pa

1 atm = 1.013 * 10⁵ Pa

1 mm Hg = 133.3 Pa

1 torr = 133.3 Pa

Scientific Notation Prefixes

1 P (Penta-) = 10¹⁵

1 T (Tera-) = 10¹²

1 G (Giga-) = 10⁹

1 M (Mega-) = 10⁶

1 k (kilo-) = 10³

1 c (centi-) = 10^-2

1 m (milli0-) = 10^-3

1 (micro-) = 10^-6

1 n (nano-) = 10^-9

1 p (pico-) = 10^-12

Common Physical Constants

Speed of light in a vacuum c = 2.99792458 * 10⁸ m/s

Gravitational Constant G = 6.67428 * 10^-11 Nm²/kg²

Planck’s Constant h = 6.62606896 * 10^-34 J s

Boltzmann Constant k = 1.3806504 * 10^-23 J/K

Avogadro’s Number N_A = 6.02214179 * 10²³ molecules / mole

Common Formulas for Area and Volume