EIRP Calculator
Calculate Effective Isotropic Radiated Power (EIRP), ERP, and power density for RF transmitters.
EIRP Parameters
EIRP = Pt - Lc + Ga
ERP = EIRP - 2.15 dB
EIRP Result
38.00 dBm
6.31 W
35.85
ERP (dBm)
8.00
EIRP (dBW)
Calculation Breakdown
TX Power+30.00 dBm
Cable Loss-2.00 dB
Antenna Gain+10.00 dBi
EIRP38.00 dBm
Power Density
@ 1 m502.10 mW/m^2
@ 10 m5.02 mW/m^2
@ 100 m50.21 mW/m^2
@ 1000 m502.10 uW/m^2
Common EIRP Limits
| Application | EIRP Limit |
|---|---|
| WiFi 2.4GHz (US) | 36 dBm (4W) |
| WiFi 5GHz (US) | 30 dBm (1W) |
| WiFi 2.4GHz (EU) | 20 dBm (100mW) |
| ISM 900MHz | 36 dBm (4W) |
| LoRa 868MHz (EU) | 14 dBm (25mW) |
| LoRa 915MHz (US) | 30 dBm (1W) |
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Editorial Note
MyCalcBuddy Editorial Team
This page is maintained as an educational calculator reference.
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Formula Source: Standard Mathematical References
by Various
🔄Last reviewed: May 2026
✓Formula checks are based on standard references and internal QA review.