Mathematical Formula Reference (Alphabetized)

A   •   B   •   C   •   D   •   E   •   F   •   G   •   H   •   I   •   J   •   K   •   L   •   M   •   N   •   O   •   P   •   Q   •   R   •   S   •   T   •   U   •   V   •   W   •   X   •   Y   •   Z

A

Antenna Length (quarter-wavelength) in feet = 234 ÷ Frequency in Megahertz (MHz)

Antenna Length (half-wavelength) in feet = 468 ÷ Frequency in Megahertz (MHz)

Antenna Length (full-wavelength) in feet = 936 ÷ Frequency in Megahertz (MHz)

Area of a Circle = π × radius 2

Area of a Square = Length of any side 2

Area of a Triangle = (1 ÷ 2) × (Base-to-Tip-Length ÷ Base Width)

Acres = Square Miles × .640

Acres = Square Feet × 2.2957 × 10--5

C

Capacitance (Parallel) in farads = 1 ÷ (C1 + C2 + Cn~ . . .)

Capacitance (Series) in farads = 1 ÷ ((1 ÷ C1) + (1 ÷ C2) + (1 ÷ Cn~) . . .)

Celsius Degrees (Co) = (5 ÷ 9) × (Farenheit Degrees − 32)

F

Fahrenheit Degrees (Fo) = ((9 ÷ 5) × Celsius Degrees) + 32

Feet (ft) = Meters × 3.281

Feet (ft) = Fathoms × 6

Feet (ft) = Yards × 3

G

Gallons (gal) = Liters × .2642

Gallons (gal) = Barrels of oil × 42

H

Horsepower (HP) = BTU per minute × .0236

Horsepower (HP) = Kilowatts (kW) × 1.341

Horsepower (HP) = Watts (W) × .0013

I

Inches (in) = Centimeter (cm) × .3937

Inches (in) = Yards × 36

Inductance (Parallel) in Henry's = 1 ÷ ((1 ÷ L1) + (1 ÷ L2) + (1 ÷ Ln~) . . .)

Inductance (Series) in Henry's = L1 + L2 + Ln~ . . .

Inductive Reactance (XL) = 2 × π × Resonant Frequency × Inductance

K

Kilowatts(kW) = Watts (W) × .001

L

LED Required Resistor Value (Ohms) = (Voltsavailable - VoltsLED maximum) ÷ MilliAmpsLED maximum

M

Miles = Kilometers × .6214

P

Pi (π) = 3.1415926535 *to 10 decimal places

Power (Watts) = Amps × Volts

Power (Watts) = Amps2 × Resistance (Ohms)

Pounds (lbs) = Ounces × .0625

R

Reactance (Capacitive) (XC) = 1 ÷ (2 × π × RESONANT_FREQUENCY × CAPACITANCE)

Reactance (Inductive) (XL) = 2 × π × RESONANT_FREQUENCY × INDUCTANCE

Resistance (Parallel) in Ohms = 1 ÷ ((1 ÷ R1) + (1 ÷ R2) + (1 ÷ Rn~) . . .)

Resistance (Series) in Ohms = R1 + R2 + Rn~ . . .

Resonant Frequency (f) = 1 ÷ ((2 × π) × SQUARE_ROOT(INDUCTANCE × CAPACITANCE))

V

Volume of a Sphere = (4 ÷ 3) × π × radius2

Volume of a Cylinder = π2 × radius × height

Volume of a Cone = (π × radius2 × height) ÷ 3

W

Watts (W) = Volts ÷ Amps