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dBm ↔ Watts ↔ Volts Converter

Power level conversions for RF work — dBm to watts to RMS/peak-to-peak volts at any system impedance.

dBm
Power
V(rms)
V(peak-to-peak)
dBm = 10log₁₀(P/1 mW) ; V(rms) = √(P·Z)
References: IEEE Std 100 (dBm definition) · Pozar, Microwave Engineering

Handy anchors: +3 dB doubles power, +10 dB is 10×, and 13 dBm = 20 mW (typical WiFi), 30 dBm = 1 W, 60 dBm = 1 kW. The voltage figures assume a matched sine into the stated impedance. Never feed more than the rated dBm into instrument inputs; +30 dBm kills most analyzers.

dBm to Watts Converter computes power levels between dBm, watts and volts at a given impedance — free, instant and private in your browser. RF techs, SDR users and lab engineers protecting instrument inputs use it to skip the datasheet algebra: type your numbers, read the answer with the substituted formula shown step by step, and share an exact permalink of the calculation.

About dBm ↔ Watts ↔ Volts Converter

dBm to Watts Converter computes power levels between dBm, watts and volts at a given impedance using the standard engineering relation: P(mW) = 10^(dBm/10); V(rms) = √(P·Z). Worked live: 30 dBm = 1 W = 7.07 V rms into 50 Ω; WiFi's 20 dBm is 100 mW. The result recalculates on every keystroke, the worked-example panel shows your numbers substituted into the formula, and the Copy permalink button encodes the inputs in the URL so a colleague opens exactly your calculation. Everything runs client-side — nothing you type leaves your device.

How to use dBm ↔ Watts ↔ Volts Converter

  1. 1Enter your values — the tool starts with realistic defaults for this exact use case, so the worked example is meaningful immediately.
  2. 2Read the live result and the worked-example panel, which substitutes your numbers into the formula step by step.
  3. 3Adjust any input to compare scenarios, then use Copy result or Copy permalink to share the calculation.

Why use dBm ↔ Watts ↔ Volts Converter?

  • Implements the real formula — P(mW) = 10^(dBm/10) — with the substitution shown, not a black box
  • Built for RF techs, SDR users and lab engineers protecting instrument inputs
  • Copy result and permalink buttons — share the exact calculation in a README, forum answer or design review
  • 100% free, no sign-up, runs entirely in your browser (works offline once loaded)

Frequently asked questions

How do you calculate dbm to watts?+

Power levels between dBm, watts and volts at a given impedance follows P(mW) = 10^(dBm/10); V(rms) = √(P·Z). For example, 30 dBm = 1 W = 7.07 V rms into 50 Ω; WiFi's 20 dBm is 100 mW. The calculator applies the same relation and shows the substituted arithmetic so you can verify every step.

What dBm levels are dangerous to equipment?+

Most spectrum analyzers and SDR front-ends spec +10 to +20 dBm absolute max — a 5 W handheld (37 dBm) keyed near them induces damage even without a direct connection. Attenuators are cheaper than mixers; when in doubt, start with 30 dB inline.

Why do RF people use dBm instead of watts?+

Link math becomes addition: +30 dBm TX, −110 dB path, +12 dB antennas = −68 dBm received — try that in watts. The log scale also spans the absurd range of RF gracefully, from −174 dBm/Hz thermal noise to 80 dBm broadcast transmitters.

Is the dBm to Watts Converter free and private?+

Yes — completely free with no sign-up or usage limits, and it runs entirely in your browser: the values you enter are never uploaded or stored on a server.

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