Decibel Calculator

Add decibel levels, convert between power/amplitude ratios and dB, and compare two sound levels.

Also known as db calculator, add decibels, db difference.

Enter values

Result

Combined level

86.76 dB

Two equal sources add only 3 dB — not double the number.

Add decibel levels, convert between power/amplitude ratios and dB, and compare two sound levels.

Also known as: db calculator, add decibels, db difference, sound comparison.

Enter calculate, level 1.
The result updates instantly as you type — press Calculate (or Enter) at any time.
Review the breakdown shown under the main result.
Use Copy result or Share to save the answer or send a link with your inputs.

L_total = 10·log₁₀(10^(L₁/10) + 10^(L₂/10))

Using the values pre-filled in the calculator above:

the calculator returns: