Return Loss ↔ VSWR Calculator
Enter either Return Loss (dB) or VSWR and click Calculate. All matching metrics are updated.
Inputs & Results
dB
:1
RL: — dB |
VSWR: — : 1
|Γ| (magnitude)
—
Reflected power
—
Delivered power
—
Mismatch loss
—
RL ≥ 0 dB and VSWR ≥ 1. If both are entered, RL is used and VSWR is ignored.
Formulas & Interpretation
Basic relationships:
- |Γ| = 10(−RL / 20)
- VSWR = (1 + |Γ|) / (1 − |Γ|)
- RL (dB) = −20 · log10(|Γ|)
Power terms:
- Reflected power % : |Γ|² × 100
- Delivered power % : (1 − |Γ|²) × 100
- Mismatch loss (dB) : −10 · log10(1 − |Γ|²)
Higher RL (in dB) and lower VSWR mean better matching and higher power transfer. A common design target is RL ≥ 20 dB (VSWR ≲ 1.22:1), but the requirement depends on the application.
Reference Table (Common Matching Points)
| RL (dB) | VSWR | |Γ| | Reflected % | Mismatch loss (dB) |
|---|