Air Core Coil Calculator (Reverse Engineering)
Design air core coils for RF/Audio. Features a 'Design Mode' to calculate required turns for a target inductance. Includes AWG/SWG wire tables.
About
Air core coils are favored in radio frequency (RF) and high-end audio applications because they are free from core saturation and hysteresis losses (distortion). However, achieving a precise inductance value requires careful mechanical design. This tool utilizes the classic Wheeler's Formula, widely regarded as the most accurate approximation for single-layer air core solenoids.
The standout feature is the Design Reverse-Engineering mode. Instead of guessing the number of turns, you can input your target inductance (e.g., 10µH) and your available coil diameter, and the tool will calculate exactly how many turns of wire are needed. It also integrates a database of American Wire Gauge (AWG) and Standard Wire Gauge (SWG) to help select the correct wire thickness.
Formulas
This tool uses the metric adaptation of Wheeler's Formula for single-layer air coils:
Where:
- L is inductance in micro-Henries (µH)
- d is coil diameter in inches
- l is coil length in inches
- n is number of turns
(The tool handles unit conversion to Millimeters automatically).
Reference Data
| AWG | Diameter (mm) | Max Current (A) | Resistance (mΩ/m) |
|---|---|---|---|
| 18 | 1.02 | 2.3 | 20.9 |
| 20 | 0.81 | 1.5 | 33.3 |
| 22 | 0.64 | 0.92 | 53.0 |
| 24 | 0.51 | 0.58 | 84.2 |
| 26 | 0.40 | 0.36 | 133.9 |
| 28 | 0.32 | 0.23 | 212.9 |
| 30 | 0.25 | 0.14 | 338.6 |