Below are some useful links for calculating various values used in electronics.
Air Core Inductor Calculator
The following is a design tool based on Weaver's formula which calculates the inductance of an air core inductor.
L = (d2 * n2) / (18d + 40l)
L is inductance in micro Henrys,
d is coil diameter in inches,
l is coil length in inches, and
n is number of turns.
Coil diameter in inches
Coil length in inches
Number of turns
LC Resonance Calculator
The following is a design tool which calculates the resonant frequency of an LC circuit.
f = 1 / (2 π )
L is inductance in Henrys,
C is capacitance in Farads, and
f is resonant frequency in Hertz.
The tool below uses more convenient values. Enter any two parameters and the calculator will present the third parameter for a resonant circuit.