ForHosting KIT · Audio & Voice

Convert decibels to linear amplitude

This decibel and linear amplitude converter changes an amplitude gain or ratio between logarithmic dB notation and a plain linear multiplier.

● BetaFree · in your browser

Run — free How it works & API

Use it from WebAPIEmailTelegramApp soon

Choose the direction, enter one finite number, and receive both representations. It uses the standard amplitude relationship of twenty times the base-ten logarithm, which is appropriate for voltage, pressure, and digital audio amplitude ratios when the compared quantities use the same reference and impedance conditions.

Understanding decibels and linear amplitude

A decibel value describes a ratio on a logarithmic scale, while a linear amplitude value describes the same ratio as an ordinary multiplier. For amplitude quantities, 0 dB corresponds to a linear amplitude of 1, meaning no gain or attenuation. A positive dB value produces a multiplier greater than 1, and a negative dB value produces a multiplier between 0 and 1. This capability uses the amplitude formula linear amplitude = 10 raised to the power of dB divided by 20. The factor is 20 because the input represents an amplitude ratio, such as voltage, sound pressure, or sample amplitude. Power ratios use a factor of 10 instead and are a different calculation. For example, approximately 6.0206 dB represents a doubling of amplitude, while approximately -6.0206 dB represents half the amplitude. The result is a dimensionless ratio; it does not establish an absolute voltage, sound pressure level, or digital full-scale level without a separate reference value.

Choosing the correct conversion direction

Select db_to_linear when the known value is expressed in decibels and you need the amplitude multiplier. This is useful when applying gain to samples, interpreting an amplifier specification, or converting an attenuation setting into a scale factor. Select linear_to_db when you already have a positive amplitude ratio and want its logarithmic representation. That direction uses dB = 20 times log base 10 of the linear amplitude. Linear amplitude must be strictly greater than zero because the logarithm of zero is not finite and the logarithm of a negative real value is undefined. The capability therefore returns an invalid-input error for zero or negative linear values instead of emitting infinity or a non-number value. Both directions require a finite numeric input. A ratio of 1 returns 0 dB, ratios above 1 return positive dB, and ratios from 0 to 1 return negative dB. Always confirm that the source quantity is an amplitude ratio rather than a power ratio before choosing this calculator.

Using results accurately in audio work

The returned value is calculated directly with JavaScript base-ten logarithm and exponentiation, without network access, random values, or time-dependent behavior. Keep enough precision through intermediate processing and round only where your display or downstream format requires it. Small rounding differences can matter when several gain stages are multiplied, although they are usually inaudible in routine level controls. A linear multiplier can be applied to digital audio samples, but it does not by itself prevent clipping: increasing amplitude may push peaks beyond the permitted sample range. Likewise, a dB result describes the ratio supplied to the converter, not an independently measured loudness change. Perceived loudness depends on frequency, duration, listening conditions, and human hearing. When comparing physical voltages or sound pressures, verify that numerator and denominator share compatible units and reference conditions. For automated workflows, the same deterministic calculation is available through the API for $0.002 per request, while the browser version can be used for quick interactive checks.

What you can do with it

Apply a gain setting to samples

Convert a dB gain or attenuation setting into the linear multiplier required by a digital signal-processing operation.

Express an amplitude ratio in dB

Turn a measured positive voltage, pressure, or sample-amplitude ratio into compact logarithmic notation.

Check audio engineering calculations

Verify gain-stage math and confirm familiar reference points such as unity gain, doubled amplitude, or half amplitude.

FAQ

What formula converts dB to linear amplitude?

The calculator uses linear amplitude = 10^(dB/20).

What formula converts linear amplitude to dB?

It uses dB = 20 × log10(linear amplitude), and the linear amplitude must be greater than zero.

Why is zero linear amplitude rejected?

The logarithm of zero is negative infinity, not a finite dB value, so the capability returns an invalid-input error.

Does this calculator convert power ratios?

No. It is specifically for amplitude ratios. Power-ratio conversion uses 10 × log10 rather than 20 × log10.

Does a 6 dB increase exactly double amplitude?

Not exactly. An exact doubling is approximately 6.020599913 dB; 6 dB gives a multiplier of about 1.9953.

What does the API conversion cost?

Each API request costs $0.002. The interactive browser calculation is available without server processing.

For developers — API access

Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.

API endpoint

POSThttps://api.kit.forhosting.com/audio/decibel-to-linear

Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.

Call it from your stack

curl -X POST https://api.kit.forhosting.com/audio/decibel-to-linear \
  -H "Authorization: Bearer $KIT_KEY" \
  -H "Content-Type: application/json" \
  -d '{"value":6,"mode":"db_to_linear"}'

const res = await fetch("https://api.kit.forhosting.com/audio/decibel-to-linear", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.KIT_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "value": 6,
    "mode": "db_to_linear"
  })
});
const { task_id } = await res.json();

import os, requests

res = requests.post(
    "https://api.kit.forhosting.com/audio/decibel-to-linear",
    headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
    json={
    "value": 6,
    "mode": "db_to_linear"
},
)
task_id = res.json()["task_id"]

<?php
$res = file_get_contents("https://api.kit.forhosting.com/audio/decibel-to-linear", false, stream_context_create([
  "http" => [
    "method"  => "POST",
    "header"  => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
    "content" => '{"value":6,"mode":"db_to_linear"}',
  ],
]));
$task = json_decode($res, true);

body := bytes.NewBufferString(`{"value":6,"mode":"db_to_linear"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/audio/decibel-to-linear", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)

Example request

{
  "value": 6,
  "mode": "db_to_linear"
}

Example response

{
  "task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
  "type": "audio.decibel_to_linear",
  "status": "queued",
  "_links": {
    "result": "/tasks/tsk_…/result"
  }
}

The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.

Pricing

Per request$0.002

Published price — no tokens, no invented credits. A failed task is never charged.

Limits

`max_mb`	200
`max_minutes`	180

Errors

HTTP	Code	Meaning
`401`	`unauthorized`	Missing or invalid API key.
`402`	`insufficient_balance`	Your balance doesn't cover the task price.
`404`	`unknown_type`	That task type doesn't exist.
`429`	`rate_limited`	Too many requests. Use the webhook instead of polling.

Read the full KIT documentation →