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Multiple Sound Sources Calculator

Combine several sound sources into one total sound level. Enter the dB level for each source to calculate the combined dB result, loudest source, quietest source, increase over the loudest source, and source contribution.

Calculate Multiple Sound Sources

Sound Source Levels

Source Type

Round Result To

Main Result Format

Show Detail Level

Sound Note

Example Preset

Total Sound Level = 10 × log10(Σ 10^(Li ÷ 10))

Your result will appear here.

How the multiple sound sources calculator works

Enter source levels:
Type each sound source level in dB. Separate values with commas, spaces, semicolons, or new lines.

Convert each source:
Each dB value is converted into a linear energy value using 10^(dB ÷ 10).

Combine sources:
The linear values are added together, then converted back into one total dB level.

Why calculate multiple sound sources?

A multiple sound sources calculator helps estimate the total noise level when several machines, speakers, fans, tools, vehicles, or environmental noise sources are operating at the same time.

This is a mathematical estimate. Real sound levels can vary based on distance, direction, reflections, phase, barriers, room conditions, and measurement location.

Multiple sound sources formula

The standard formula for combining multiple sound sources is:

Total dB = 10 × log10(Σ 10^(Li ÷ 10))

Li = each individual sound source level in dB
Σ = sum of all source energy values
10^(Li ÷ 10) = each dB source converted into linear energy
Total dB = combined sound level from all sources

Multiple sound source calculator tips

Use this calculator when sources are independent and measured at the same listener or receiver location.
Use the dB level for each source at the point where you want the combined result.
Do not add 70 dB + 70 dB as 140 dB. The correct combined result is about 73 dB.
If one source is 10 dB louder than another, the quieter source adds only a small amount to the total.
For real sites, distance, walls, reflections, and direction can change the measured total.

Frequently asked questions

How do you combine multiple sound sources?

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

What is the total of three 70 dB sound sources?

Three equal 70 dB sound sources combine to about 74.8 dB, because three equal sources add about 4.8 dB.

Why can’t I add sound sources normally?

Decibels are logarithmic. Normal arithmetic does not work because dB values represent ratios, not direct linear quantities.

Does this calculator account for distance?

No. Enter the dB level for each source at the same receiver location. If the source levels are measured at different distances, use a distance sound calculator first.