Free Engineering Tool #216
Sound Level Converter
Convert between unweighted sound pressure level (dB SPL) and sound pressure (Pa). Enter a value in either unit and get an instant conversion. Note: A-weighted levels in dB(A) are not directly convertible to Pa.
Results
Sound Pressure Level
where p₀ = 20 μPa = 2 × 10⁻⁵ Pa (threshold of hearing)
A Note on dB(A)
This converter works with unweighted sound pressure levels (dB SPL). An A-weighted level, dB(A), applies a frequency-dependent correction curve that approximates human hearing sensitivity. Because the correction varies with frequency, a single dB(A) value cannot be converted to sound pressure in Pa without knowing the frequency spectrum of the sound. Do not enter dB(A) readings into this tool expecting an exact pressure value.
Common Sound Levels
| Level (dB) | Pressure (Pa) | Example |
|---|---|---|
| 0 | 0.00002 | Hearing threshold |
| 30 | 0.00063 | Quiet room |
| 60 | 0.02 | Normal conversation |
| 85 | 0.36 | Heavy traffic |
| 94 | 1.0 | 1 Pascal reference |
| 120 | 20.0 | Pain threshold |
| 140 | 200.0 | Jet engine (close) |
p = p₀ × 10^(SPL/20), where p₀ = 20 μPa. For example, 94 dB = 1 Pa.
20 μPa (2×10⁻⁵ Pa), the approximate threshold of hearing at 1 kHz.
A-weighting adjusts levels to match human hearing. It reduces low (<500 Hz) and very high (>6 kHz) frequencies. dBA is the standard occupational noise unit. Because the correction is frequency-dependent, a single dB(A) value cannot be converted to Pa without the frequency spectrum — this tool converts unweighted dB SPL only.
0 dB SPL = 20 μPa, the quietest sound most people can detect. Not silence, but extremely quiet.
Approximately 130–140 dB SPL, corresponding to 63–200 Pa of sound pressure.
The procedures described on this page were developed and field-tested by the Vibromera team using the Balanset-1A, a portable dual-channel balancer and vibration analyzer for on-site rotor balancing.
Professional vibration instruments.
Nikolai Shelkovenko
Nikolai Shelkovenko is a vibration analysis engineer and the founder and CEO of Vibromera. For more than 15 years he has balanced rotating equipment in the field rather than on a test bench: mulchers, industrial fans, crushers, centrifuges, shafts and spindles. That work is what the Balanset instruments grew out of — they were designed as a tool a specialist can carry to the machine and use alone, on site, not as laboratory equipment. Vibromera was founded in 2017 and has been based in Porto, Portugal, since 2023. Development, assembly and support of the Balanset line all happen here. The flagship instrument is the Balanset-1A, a portable analyser for single- and two-plane balancing and for vibration diagnostics. Nikolai is personally involved in customer support, in working through difficult balancing cases and in the development of the software. He works with customers worldwide, in any language.
