Power (mW) → Final (dBm)
1 mW → 0 dBm
10 mW → +10 dBm
20 mW → +13 dBm
30 mW → +15 dBm
50 mW → +17 dBm
Step-by-Step Calculation
6db/ loss per km
Distance (km) Loss (dB) Remaining Power (dBm) Visible?
1 km 6 17 - 6 = +11 dBm Very bright
2 km 12 17 - 12 = +5 dBm Clearly visible
3 km 18 17 - 18 = −1 dBm Visible but dim
4 km 24 17 - 24 = −7 dBm Very weak
5 km 30 17 - 30 = −13 dBm Often not visible
6 km 36 17 - 36 = −19 dBm Almost invisible
