dB Addition Calculator

Add multiple decibel levels correctly using logarithmic addition. Enter sound levels in dB to calculate the combined total level, energy sum, loudest source, correction amount, and step-by-step calculation.

Add Decibel Levels

Total dB = 10 × log10(10^(L1/10) + 10^(L2/10) + ...)
Your result will appear here.

How the dB addition calculator works

Enter levels:
Type two or more dB levels separated by commas, spaces, or new lines.

Convert to linear energy:
Each level is converted using 10 raised to the dB divided by 10.

Add and convert back:
The linear values are added together, then converted back to decibels using 10 × log10.

Why dB addition is different

Decibels use a logarithmic scale, so they do not add like regular numbers. A 60 dB sound plus another 60 dB sound equals about 63 dB because the acoustic energy doubles, not because the dB numbers are added directly.

This calculator is useful for combining multiple sound sources, equipment noise levels, machine noise levels, speaker levels, environmental noise estimates, and acoustic comparisons.

dB addition formula

The standard formula for adding multiple decibel levels is:

Total dB = 10 × log10(Σ 10^(Li ÷ 10))

dB addition calculator tips

Frequently asked questions

How do you add decibels?

Convert each dB value to linear energy using 10^(dB ÷ 10), add the linear values, then convert back using 10 × log10(total energy).

What is 60 dB plus 60 dB?

60 dB plus 60 dB equals about 63 dB, because two equal sound sources add about 3 dB.

Why is 60 dB plus 60 dB not 120 dB?

Decibels are logarithmic. Adding two equal 60 dB sources doubles the energy, which is a 3 dB increase, not a direct arithmetic sum.

Can I add more than two dB levels?

Yes. Enter multiple levels separated by commas, spaces, or new lines. The calculator will add all valid dB values using logarithmic addition.