SWR Power Loss Calculator
Calculate percentage of power lost from SWR mismatch. Shows reflected power, mismatch loss, additional feedline loss, and power delivered to antenna.
Inputs
W
dB
Results
Power to Antenna
66.66 W
Power Reflected
11.11 W
System Efficiency
66.7 %
Power Reflected11.1 %
Mismatch Loss0.512 dB
Extra Feedline Loss (SWR)0.25 dB
Total System Loss1.76 dB
Safe for RigYes
How to Use This Calculator
- Enter your measured SWR from your antenna analyzer or transmitter's built-in meter.
- Set transmit power (W) and matched feedline loss (dB per 100 ft at your frequency).
- Review power delivered to the antenna, power reflected (W and %), and total mismatch loss (dB).
- Check additional feedline loss due to SWR — high SWR significantly increases cable losses.
- Use the results to decide if an antenna tuner or antenna adjustment is warranted.
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Formula
Γ = (SWR-1)/(SWR+1); Reflected% = Γ² × 100Related Calculators
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