
dB Calculator Plus
Sound Pressure Intensity Level
0 ratings
Archived App (Last seen on 30 May 2026)
This is an archived listing of the app previously available on the App Store.Although the app is no longer distributed by Apple, you can still view its description, screenshots, version history, ratings, and metadata for reference.
About
dB Calculator is a physics/math calculator designed to find sound pressure level (SPL) and sound intensity level (SIL) in decibels quickly and easily.
Features:
- Instant calculation.
- Results are copyable to other apps.
- Formulas are included as a reference.
- Support up to 16 decimal places.
- Works seamlessly on both iPhone and iPad.
- Lightweight, compact app optimized for everyday use.
- Ad-free and built with privacy in mind.
Sound pressure level (SPL)
SPL is a ratio of the absolute sound pressure to a reference level, usually the Threshold of Hearing, or the lowest intensity sound that can be heard by most people. SPL is measured in decibels (dB) due to the broad range of intensities we can hear.
Formula:
SPL = 20 * log (P/Pref)
Where:
SPL - is the sound pressure level in dB
P - is the sound wave pressure, measured in pascals
Pref - is the reference value of sound pressure, typically assumed to be equal to 0.00002 Pa
Sound intensity level (SIL)
Sound intensity is defined as the sound power per unit area, typically measured in the air at a listener's location. The basic units are watts/m² or watts/cm².
Formula:
SIL = 10 * log (I/Iref)
Where:
SIL - is the sound intensity level in dB
I - is the sound intensity in watts per squared meter
Iref - is the reference value of sound intensity, typically assumed to be equal to 10⁻¹² W/m²
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What's New in dB Calculator Plus
1.3
March 8, 2026
- Updated for the newest devices. - Minor bugs fixed.









