Constants and Conversion Factors

Atomic weights

C = 12

Ca = 40

Cl = 35.5

Fe = 55.8

H = 1

K = 39.1

N = 14

Na = 23

O = 16

S = 32

P = 31

Molecular weights

Water = 18

Amino acid average = 135

DNA base pair average = 610

Glucose = 180

Dry air = 28.84

Protein = 5000 to 3(10)⁶

meters to microns

1m = 10⁶ microns

meters to nanometers

1m = 10⁹ nm

meters to angstroms

1m = 10¹⁰ angstrom

yards to centimeters

1yd = 91.44 cm

miles to feet

1mi = 5280ft

miles to kilometers

1mi = 1.61km

typical mammalian cell length

10 microns

cubic meters to liters to cubic centimeters to milliliters

1m² = 1000L = 10⁶ cm³ = 10⁶ mL

cubic feet to gallons to liters

1ft³ = 7.48 gal = 28.3 L

whole blood volume

5L

resting cardiac output

5L/min

total lung capacity

6.0L

tidal volume

0.500L

average breathing frequency

12 breaths / min

kilograms to metric tons to pounds mass

1kg = 0.001 metric tons = 2.2lb_m

pounds mass to ounces to grams

1lb_m = 16oz = 454g

grams per cubic centimeter to pounds mass per cubic feet

1g/cm³ = 62.4lb_m/ft³

gram moles (often called mol) to pound moles

1g-mol = 0.00220lb-mol

millimeters of mercury to liters of 1 gmol of ideal gas at 0 degrees Celsius

760mmHg = 22.4L

psia to cubic feet of 1lb-mol of ideal gas at 32 degrees Fahrenheit

14.7psia = 359ft³

atmospheres to millimeters of mercury at zero degrees Celsius to pounds force per square inch

1atm = 760torr = 14.7psi

atmospheres to inches of mercury to feet of water (burial pressure)

1atm = 29.92 in Hg = 34ft. H₂O

atmospheres to bar to kilopascals to dynes per square centimeter

1atm = 1.013bar = 101.3kPa = 1.013(10⁶ dynes/cm²

pascal to newtons per square meter

1Pa = 1N/m²

systemic blood pressure

120/80 mmHg

degrees Fahrenheit to degrees Celsius

F = 1.8(C) + 32

Rankine to Fahrenheit

1R = 1F + 460

Kelvin to Celsius

1K = 1C + 273

room temp in Celsius

25C

Body core temperature

37C

pounds force to pounds mass by feet per square second to newtons to kilograms by meters per square second to dynes

1lb_f = 32.174 lbm(ft)/s² = 4.448N = 4.48kg(m)/s² = 4.448(10)⁵ dynes

dry air composition by volume & mole percentage

79% N2, 21%O2

dry air composition by weight composition

76% N2, 24% O2

Standard Temperature and Pressure (STP)

0 degrees Celsius and 1atm

btu to cal to foot pound force to joules

1btu = 252cal = 778 ft-lb_f 1055J

joules to dynes-cm

1J = 10⁷ dynes-cm

food calories to calories

1kcal = 1000cal

kilowatts to joules per second to hp to calories per second

1kW = 1000J/s = 1.34hp = 239cal/s