Single-Layer Inductors w/ Air Cores

• L = a² * N² / ((9 * a) + (10 * b))
• N = √(L * ((9 * r) + (10 * A)) / r²)

Where:

• L = Inductance in µH
• N = Number of Turns
• a = Coil Diameter in inches
• b = Coil Length in inches

Notes:

• Diameter and length are measured center-to-center of the wire, not overall.
• These formulas are most accurate when the coil length is >2x the diameter and the frequency is less than 10 MHz.