Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Resulting ratio (multiplier)
0.5012
Percent change
-49.9%
dB change to reverse this
6.0
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter db change.
- 2Enter quantity type.
- 3Read your resulting ratio (multiplier) on the right — it updates as you type.
- 4Hit Share to keep the scenario or send it to someone.
About this calculator
Decibels are logarithmic, so a 'small' number like -10 dB actually means one-tenth the power, and -6 dB roughly halves the voltage/amplitude. This calculator converts a dB change into the resulting ratio for either power or voltage/amplitude quantities — the two follow different formulas because power is proportional to voltage squared, which trips up a lot of people mixing up fader levels with actual signal reduction.
Worked example
Using the values the calculator loads with:
Inputs
- dB change: -6
- Quantity type: Voltage / amplitude / SPL
Results
- Resulting ratio (multiplier): 0.5012
- Percent change: -49.9%
- dB change to reverse this: 6
What each field means
Inputs
- dB change
- The db change used in the calculation. Starts at -6 so you have a working example on load. Accepted range: -100–100.
- Quantity type
- Pick the option that matches your situation — the maths changes per option. Choices: Voltage / amplitude / SPL, Power.
Results
- Resulting ratio (multiplier)
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Percent change
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- dB change to reverse this
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why is -6 dB roughly half and -10 dB a tenth, using different exponents?
Power dB uses 10×log10(ratio) because power relates directly to energy, while voltage/amplitude dB uses 20×log10(ratio) because power is proportional to voltage squared — doubling voltage quadruples power, so the exponent doubles to keep both scales consistent for the same physical event. That's why -6 dB voltage ≈ half amplitude, but -3 dB power ≈ half power.
Which one should I use for a fader or gain knob?
Mixing console faders and most plugin gain controls are calibrated in voltage/amplitude dB, so use that setting for gain staging, trim, and EQ questions. Use power dB when working with acoustic power, RF, or amplifier wattage output ratings.
How does this relate to perceived loudness?
Human hearing perceives roughly a 10 dB increase as 'twice as loud' subjectively, even though that's a 10x power increase — loudness perception is its own logarithmic curve on top of the physical dB scale, which is why small dB moves can sound bigger or smaller than the math suggests.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). dB Attenuation Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/db-attenuation
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/db-attenuation" target="_blank" rel="noopener">dB Attenuation Calculator — RevenueLab</a> (2026).</p>
Source: [dB Attenuation Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/db-attenuation) (2026).