Can I simply add decibels together?

No. Decibels are logarithmic. Two equal sources each at 80 dB produce 83 dB combined, not 160 dB.

What is the formula for adding decibels?

L_total = 10 × log10(10^(L1/10) + 10^(L2/10) + ...) for incoherent sources.

Decibel Addition Calculator

Add multiple decibel levels together correctly using logarithmic addition. Calculate the combined SPL from several independent noise sources.

2D stress state at a point. All stresses in MPa.

σx — Normal Stress X (MPa)

σy — Normal Stress Y (MPa)

τxy — Shear Stress (MPa)

⚙ Mechanical Note: Results are based on standard textbook formulas and ISO/AASHTO references. Always verify critical designs with applicable codes (ISO 898, AASHTO 1993, AISC, Eurocode 3) and a qualified engineer.

How It Works

Add multiple decibel levels together correctly using logarithmic addition. Calculate the combined SPL from several independent noise sources

Each component has a specific meaning:

Logarithmic addition — The logarithmic addition recorded for the scenario being assessed.

Note: Interpret the db addition result against the thresholds and context described above.

How to Use

Enter the logarithmic addition for the scenario you are assessing. Add multiple decibel levels together correctly using logarithmic addition. Calculate the combined SPL from several independent noise sources. Use the db addition result to inform your calculation.

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