Sound intensity level calculator (dB)
Enter the sound intensity to get its level in decibels and its ratio to the hearing threshold. Suited to physics and acoustics problems.
Loading the tool…
Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter sound intensity.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
L = 10 × log₁₀(I / I₀), where I₀ = 10⁻¹² W/m² is the reference intensity.
Example
Inputs: Sound intensity = 0.00001 W/m². Result: Sound intensity level: 70 dB; Ratio to threshold: 10,000,000.
Limits and caveats
- This is an unweighted physical level; it does not reflect the ear's frequency sensitivity the way dB(A) does.
Questions about this tool
What does a 10 dB increase mean?
The intensity is 10 times higher, and most people hear it as roughly twice as loud.
What is 0 dB?
It is the reference intensity 10⁻¹² W/m², close to the faintest 1000 Hz tone a healthy ear can hear.
Can the level be negative?
Yes, when the intensity is below the reference value.