Documentation sections

dBm Power Converter

POSThttps://rftools.io/api/py/v1/calculate

Slug db-converter. Convert dBm to watts, milliwatts, dBW, dBuV, and Vrms instantly. Enter power level and impedance for all RF power unit conversions. Free, instant results.

Inputs

Send every one of these in inputs, in the units shown. Most are required: a call without one is refused (400) and costs nothing; one the calculator can do without takes the default shown. An input outside its range is still computed and flagged in the provenance.

Inputs of db-converter
Name	Unit	Range	Default	Description
dbmnumber	dBm	−150 … 100	0	Power in dBm (0 dBm = 1 mW)
impedancenumber	Ω	1 … 10000	50	Reference impedance for voltage conversion (typically 50Ω or 75Ω)

Outputs

Returned in values, by key. A value that is unbounded or undefined is null.

Outputs of db-converter
Field	Unit	Description
dbw	dBW	Power
wattsheadline	W	Power
mwatts	mW	Power
uwatts	μW	Power
vrms	V RMS	Voltage
mvrms	mV RMS	Voltage
dbuv	dBμV	Voltage

Calling it

Calculate: one call, the request and response in full, and its errors.
Batch: this calculator with others, or a sweep, in one request.
Solve for a target: the value of one input that brings an output to a target.

curl -X POST https://rftools.io/api/py/v1/calculate \
  -H "X-API-Key: $RFTOOLS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "slug": "db-converter",
    "inputs": {
      "dbm": 0,
      "impedance": 50
    }
  }'

import rftools

client = rftools.Client()  # reads RFTOOLS_API_KEY, or the key `rftools login` saved

result = client.calculate("db-converter", {"dbm": 0, "impedance": 50})
print(result.values)
print(result.warnings, result.provenance.formula_ref)

const response = await fetch("https://rftools.io/api/py/v1/calculate", {
  method: "POST",
  headers: {
    "X-API-Key": process.env.RFTOOLS_API_KEY,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "slug": "db-converter",
    "inputs": {
      "dbm": 0,
      "impedance": 50
    }
  }),
});
console.log(response.status, await response.json());

package main

import (
	"bytes"
	"fmt"
	"io"
	"net/http"
	"os"
)

func main() {
	body := []byte(`{
	  "slug": "db-converter",
	  "inputs": {
	    "dbm": 0,
	    "impedance": 50
	  }
	}`)
	req, err := http.NewRequest("POST", "https://rftools.io/api/py/v1/calculate", bytes.NewReader(body))
	if err != nil {
		panic(err)
	}
	req.Header.Set("X-API-Key", os.Getenv("RFTOOLS_API_KEY"))
	req.Header.Set("Content-Type", "application/json")
	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()
	out, _ := io.ReadAll(res.Body)
	fmt.Println(res.Status, string(out))
}

application/json

{
  "slug": "db-converter",
  "values": {
    "dbw": -30,
    "watts": 0.001,
    "mwatts": 1,
    "uwatts": 1000,
    "vrms": 0.22360679774997896,
    "mvrms": 223.60679774997897,
    "dbuv": 106.98970004336019
  },
  "warnings": [],
  "errors": [],
  "provenance": {
    "method": "calculator:db-converter",
    "version": "api@3f2c1a9b04de",
    "formulaRef": "Microwave Engineering, 4th ed., David M. Pozar (2011), Chapter 1 — dBm and power units",
    "assumptions": [],
    "validRange": {
      "status": "inside",
      "bounds": {
        "dbm": {
          "min": -150,
          "max": 100,
          "unit": "dBm"
        },
        "impedance": {
          "min": 1,
          "max": 10000,
          "unit": "Ω"
        }
      },
      "outside": [],
      "model": null
    },
    "computedAt": "2026-09-24T14:05:11.003Z",
    "inputs": {
      "dbm": 0,
      "impedance": 50
    },
    "seed": null,
    "elapsedSeconds": 0.003
  }
}

{
  "detail": [
    {
      "type": "float_parsing",
      "loc": [
        "body",
        "inputs",
        "dbm"
      ],
      "msg": "Input should be a valid number, unable to parse string as a number",
      "input": "abc"
    }
  ]
}

An input sent as text. Nothing was counted.

{
  "detail": "More than 120 requests in 60 seconds from this address.",
  "errorKind": "rate_limited",
  "limit": 120,
  "windowSeconds": 60,
  "upgradeUrl": "https://rftools.io/pricing/"
}

Too many requests in a minute, with Retry-After.

Same inputs on the calculator pagedBm Power Converter, at these values