RF Power & Link Calculator (dBm, EIRP, Path Loss)
Convert dBm, dBW, watts and dBµV; work out EIRP/ERP, free-space path loss, power density at a distance and VSWR ↔ return loss.
Power
1 mW
- dBm
- 0 dBm
- dBW
- -30 dBW
- Watts
- 1 mW
- dBµV (50 Ω)
- 106.99 dBµV
- Voltage across 50 Ω
- 0.223607 V rms
dBµV assumes the power is delivered into a matched 50 Ω load (V = √(P·Z)).
Show the work
Power
PW = 10 to the power of dBm ÷ 10 ÷ 1000
10 to the power of 0 ÷ 10 ÷ 1000 = 1 mW
How it works
dBm = 10·log₁₀(P / 1 mW). dBµV = 20·log₁₀(√(P·Z) / 1 µV). EIRP = P + G − L; ERP = EIRP − 2.15 dB. FSPL = 20·log₁₀(4π·d·f / c). S = EIRP ÷ (4π·d²). |Γ| = (VSWR − 1) ÷ (VSWR + 1), return loss = −20·log₁₀|Γ|.
dBµV assumes a matched load of the impedance you pick (50 Ω or 75 Ω). Path loss and power density assume free space, isotropic antennas and the far field. A half-wave dipole is 2.15 dBi, so dBd = dBi − 2.15. c = 299,792,458 m/s (exact).
Questions
- How does the RF power & link calculator work?
- dBm = 10·log₁₀(P / 1 mW). dBµV = 20·log₁₀(√(P·Z) / 1 µV). EIRP = P + G − L; ERP = EIRP − 2.15 dB. FSPL = 20·log₁₀(4π·d·f / c). S = EIRP ÷ (4π·d²). |Γ| = (VSWR − 1) ÷ (VSWR + 1), return loss = −20·log₁₀|Γ|.
- What does it assume?
- dBµV assumes a matched load of the impedance you pick (50 Ω or 75 Ω). Path loss and power density assume free space, isotropic antennas and the far field. A half-wave dipole is 2.15 dBi, so dBd = dBi − 2.15. c = 299,792,458 m/s (exact).
- What is 0 dBm in watts?
- 0 dBm is 1 milliwatt; 30 dBm is 1 watt; every 10 dB is ×10 in power.
- Why does path loss grow with frequency?
- FSPL counts the loss between two isotropic antennas; a higher frequency has a smaller antenna aperture, so it collects less of the spreading power.
Related tools
- Electric Charge ConverterConvert electric charge — coulombs, ampere-hours, milliamp-hours, faradays and more.
- Linear Charge Density ConverterConvert charge per unit length — C/m, C/cm, C/in and CGS units.
- Surface Charge Density ConverterConvert charge per unit area — C/m², C/cm², µC/cm² and more.
- Volume Charge Density ConverterConvert charge per unit volume — C/m³, C/cm³, C/L and more.
- Electric Current ConverterConvert amperes, milliamps, microamps, kiloamps and CGS current units.
- Linear Current Density ConverterConvert current per unit length — A/m, A/cm, A/in and more.
Want this on your site? Embed the rf power & link calculator (dbm, eirp, path loss).