This calculator estimates the minimum and recommended power supply size for your ham radio station based on voltage, current draw, and headroom.

It uses the formula: \[ P = V \times I \quad \text{and} \quad P_{\text{rec}} = P \times (1 + \frac{\text{headroom}}{100}) \] Where:

• V: Operating voltage (e.g. 13.8V DC)
• I: Total current draw in amps
• Headroom: Safety margin to avoid overload and heat stress

The recommended power supply should be rated for the result in either watts or amps. Most modern HF radios draw 20–25A max on transmit, so add accessories accordingly.