Mathematics · Algebra

Audio Amplitude Gain in Decibels Calculator

Calculate amplitude gain decibels from output amplitude and input amplitude.

Runs locally
Your numbers

Inputs and results stay in this browser. Change one value at a time to explore the relationship.

Your inputCalculatedPassed forward in chains
amplitude gain decibels12.0412

Calculation steps

  1. Use c=20log₁₀(a/b) with output amplitude=2 and input amplitude=0.5.
  2. amplitude gain decibels=12.041199826559247.

Understand Audio Amplitude Gain in Decibels

One idea, three depths

Choose how deeply to explain Audio Amplitude Gain in Decibels

Audio Amplitude Gain in Decibels: Calculate amplitude gain decibels from output amplitude and input amplitude.

Age 5Explain it to a 5-year-oldStart with a picture

Imagine using Audio Amplitude Gain in Decibels to answer this question: calculate amplitude gain decibels from output amplitude and input amplitude? Enter output amplitude and input amplitude; the calculator shows amplitude gain decibels. For example: output amplitude=2 and input amplitude=0.5 produce amplitude gain decibels=12.041199826559247. The answer tells you amplitude gain decibels.

Age 15Explain it to a 15-year-oldConnect it to the formula

For like impedances and amplitude quantities, gain in decibels is twenty times the base-ten logarithm of output-to-input ratio. This page evaluates the relationship directly. The rule is c=20log₁₀(a/b). Its input values are output amplitude, input amplitude, and the main result is amplitude gain decibels. For example: output amplitude=2 and input amplitude=0.5 produce amplitude gain decibels=12.041199826559247.

CollegeExplain it at college levelState the model precisely

This calculator evaluates the stated audio amplitude gain in decibels relation over the valid real-number domain stated below. The implemented relation is c=20log₁₀(a/b), evaluated from output amplitude, input amplitude to produce amplitude gain decibels. For like impedances and amplitude quantities, gain in decibels is twenty times the base-ten logarithm of output-to-input ratio. This page evaluates the relationship directly. Use ten times the logarithm for a direct power ratio and never take a logarithm of zero or a signed amplitude.

Inputs and valid domain

  • output amplitude must be a finite real number.
  • input amplitude must be a finite real number.

Important boundary: Use ten times the logarithm for a direct power ratio and never take a logarithm of zero or a signed amplitude.

The formula

c=20log₁₀(a/b)

How the calculator works through it

It substitutes output amplitude, input amplitude into the formula and exposes every numerical step above. The main output is amplitude gain decibels.

Read the result correctly

The amplitude gain decibels is the direct answer to “calculate amplitude gain decibels from output amplitude and input amplitude.” Read it with the units shown beside the inputs; a sign, angle, percentage or rate changes what the number means.

A worked check

output amplitude=2 and input amplitude=0.5 produce amplitude gain decibels=12.041199826559247.

Where this model stops being reliable

Use ten times the logarithm for a direct power ratio and never take a logarithm of zero or a signed amplitude.

Learn it by changing one value

Begin with the worked example, then change one value while keeping the others fixed. Compare the new result and calculation steps to identify which part of the formula changed.

Dictionary terms behind this calculator

Before studying the codeWhat you should know firstUse the calculator immediately, or check the foundations before reading the implementation.

These foundations help you understand why Audio Amplitude Gain in Decibels works. They never block the calculator, and “optional” means useful context rather than a hidden requirement.

Hard requirements

  • Reading formulas and substituting values

    Audio Amplitude Gain in Decibels uses c=20log₁₀(a/b). You need to recognise what each side represents before substituting the stated inputs or rearranging the relationship.

    Review this foundation about 4 min

Strong support

Optional enrichment

  • Powers and exponents

    Powers are not required for every Audio Amplitude Gain in Decibels calculation, but they make related algebraic forms and code easier to read.

    Review this foundation about 4 min
Learn the missing foundationsI already know these — show the code

Mathematics → algorithm → program

Implement this calculation in code

These are direct reference implementations of the calculator's principal relationship and first output. They run locally and include a small known-answer check where the language supports it.

Algorithm

  1. Read output amplitude, input amplitude.
  2. Evaluate the principal relationship: c=20log₁₀(a/b).
  3. Return amplitude gain decibels and check the domain conditions described above.
Python
            from math import *

def audio_amplitude_gain_decibels_calculator(a, b) -> float:
    return ((20.0 * log((a / b))) / log(10.0))

assert abs(audio_amplitude_gain_decibels_calculator(2, 0.5) - 12.041199826559247) < 1e-6 * max(1.0, abs(12.041199826559247))
          
Current calculator valuesUpdates when you change an input above.
              
            
C
            #include <assert.h>
#include <math.h>

double audio_amplitude_gain_decibels_calculator(double a, double b) {
    return ((20.0 * log((a / b))) / log(10.0));
}

int main(void) {
    const double expected = 12.041199826559247;
    const double actual = audio_amplitude_gain_decibels_calculator(2, 0.5);
    assert(fabs(actual - expected) < 1e-6 * fmax(1.0, fabs(expected)));
}
          
Current calculator valuesUpdates when you change an input above.
              
            
C++
            #include <cassert>
#include <cmath>
#include <numbers>

double audio_amplitude_gain_decibels_calculator(double a, double b) {
    return ((20.0 * std::log((a / b))) / std::log(10.0));
}

int main() {
    constexpr double expected = 12.041199826559247;
    const double actual = audio_amplitude_gain_decibels_calculator(2, 0.5);
    assert(std::fabs(actual - expected) < 1e-6 * std::fmax(1.0, std::fabs(expected)));
}
          
Current calculator valuesUpdates when you change an input above.
              
            
Linux x86-64 assembly

x86-64 NASM · System V ABI · Linux · SSE2 with libm where required

            ; double audio_amplitude_gain_decibels_calculator(double a, double b)
; Linux x86-64 NASM · System V ABI · first eight doubles in xmm0–xmm7
extern log
global audio_amplitude_gain_decibels_calculator
section .text

audio_amplitude_gain_decibels_calculator:
    push rbp
    mov rbp, rsp
    sub rsp, 80
    movsd [rbp-8], xmm0
    movsd [rbp-16], xmm1
    mov rax, 0x4034000000000000
    movq xmm0, rax
    movsd [rbp-40], xmm0
    movsd xmm0, [rbp-8]
    divsd xmm0, [rbp-16]
    movsd [rbp-56], xmm0
    movsd xmm0, [rbp-56]
    call log wrt ..plt
    movsd [rbp-48], xmm0
    movsd xmm0, [rbp-40]
    mulsd xmm0, [rbp-48]
    movsd [rbp-32], xmm0
    mov rax, 0x4024000000000000
    movq xmm0, rax
    movsd [rbp-72], xmm0
    movsd xmm0, [rbp-72]
    call log wrt ..plt
    movsd [rbp-64], xmm0
    movsd xmm0, [rbp-32]
    divsd xmm0, [rbp-64]
    movsd [rbp-24], xmm0
    movsd xmm0, [rbp-24]
    leave
    ret
          
Current calculator valuesUpdates when you change an input above.
              
            
MATLAB
            function result = audio_amplitude_gain_decibels_calculator(a, b)
    result = ((20.0 * log((a / b))) / log(10.0));
end
          
Current calculator valuesUpdates when you change an input above.
              
            
Wolfram Language
            ClearAll[mwCalculate];
mwCalculate[a_, b_] := ((20.0 * Log[(a / b)]) / Log[10.0]);
          
Current calculator valuesUpdates when you change an input above.
              
            

Continue in mathematical software

The downloaded file includes your current inputs and first calculated result. It is created locally.

Floating-point answers can differ slightly by language, compiler and processor. Compare within a suitable tolerance rather than assuming every decimal representation will be identical.

Supporting sourcesAcademic referencesPrimary standards, textbooks and complete citations

Standards, reading and academic references

Use the calculator as the worked interaction, then consult the primary standards and academic textbooks listed below. MW SysArc links to the original sources; the explanation on this page is original and does not reproduce them.

Algebra and Trigonometry 2e

Read the related free OpenStax mathematics chapters
Cite this book
APA 7
Abramson, J. (2021). Algebra and trigonometry 2e. OpenStax. https://openstax.org/books/algebra-and-trigonometry-2e/pages/1-introduction-to-prerequisites
MLA 9
Abramson, Jay. Algebra and Trigonometry 2e. OpenStax, 2021, https://openstax.org/books/algebra-and-trigonometry-2e/pages/1-introduction-to-prerequisites.
Chicago author-date
Abramson, Jay. 2021. Algebra and Trigonometry 2e. Houston, TX: OpenStax. https://openstax.org/books/algebra-and-trigonometry-2e/pages/1-introduction-to-prerequisites.

OpenStax entries are free to read online. Follow the licence shown on each linked source before redistributing or adapting its content.

Reuse the page responsiblyCite this pageAPA, MLA, Chicago, Harvard, BibTeX and RIS

These formats cite this calculator page itself. They are separate from the academic references above, which support the mathematical method and terminology.

APA 7

MW SysArc. (2026, July 21). Audio Amplitude Gain in Decibels Calculator. MW SysArc Tools. https://math.mwsysarc.com/algebra/audio-amplitude-gain-decibels-calculator

MLA 9

MW SysArc. “Audio Amplitude Gain in Decibels Calculator.” MW SysArc Tools, 21 July 2026, https://math.mwsysarc.com/algebra/audio-amplitude-gain-decibels-calculator. Accessed 31 Aug. 2026.

Chicago 17

MW SysArc. “Audio Amplitude Gain in Decibels Calculator.” MW SysArc Tools. Published July 21, 2026. Accessed August 31, 2026. https://math.mwsysarc.com/algebra/audio-amplitude-gain-decibels-calculator.

Harvard

MW SysArc (2026) ‘Audio Amplitude Gain in Decibels Calculator’, MW SysArc Tools. Published 21 July 2026. Available at: https://math.mwsysarc.com/algebra/audio-amplitude-gain-decibels-calculator (Accessed: 31 August 2026).

BibTeX and RIS records

BibTeX

@misc{mwsysarc_audio_amplitude_gain_decibels_calculator_2026,
  author = {{MW SysArc}},
  title = {Audio Amplitude Gain in Decibels Calculator},
  howpublished = {MW SysArc Tools},
  year = {2026},
  url = {https://math.mwsysarc.com/algebra/audio-amplitude-gain-decibels-calculator},
  note = {Published July 21, 2026; accessed August 31, 2026}
}

RIS

TY  - ELEC
AU  - MW SysArc
TI  - Audio Amplitude Gain in Decibels Calculator
T2  - MW SysArc Tools
PY  - 2026
DA  - 2026-07-21
Y2  - 2026-08-31
UR  - https://math.mwsysarc.com/algebra/audio-amplitude-gain-decibels-calculator
N1  - Published July 21, 2026
ER  -

Clear answers

Frequently asked questions

What does the Audio Amplitude Gain in Decibels do?

Calculate amplitude gain decibels from output amplitude and input amplitude.

How does the Audio Amplitude Gain in Decibels work?

The calculator applies c=20log₁₀(a/b). For like impedances and amplitude quantities, gain in decibels is twenty times the base-ten logarithm of output-to-input ratio. This page evaluates the relationship directly.

What can I learn from the Audio Amplitude Gain in Decibels?

It connects the mathematical rule to your chosen numbers and shows each calculation step. Change one input at a time to see how the result responds.

Does MW SysArc receive or store what I enter?

No. The calculation runs locally in your browser. MW SysArc does not receive or store your calculation inputs.

How should I use the result?

Use the steps to understand the method, then verify important school or professional work using the notation and rounding rules required in your setting.

Last reviewed . Calculations tested .

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