What this calculator does
Sound intensity level (decibels) works out decibel level of a sound from its intensity, referenced to the hearing threshold. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaL = 10·log₁₀(I / I₀), I₀ = 1×10⁻¹² W/m²
The inputs explained
| Field | What to enter |
|---|---|
| Sound intensity (W/m²) | A number, measured in W/m². Starts at 0.000001. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with sound intensity
Every other input is held at the calculator’s starting values while sound intensity varies. Select any row to load that scenario into the calculator.