Decibel re 1 µPa (underwater) to Decibel SPL (re 20 µPa) Converter
0 dB re 1 µPa is about -26.02059991 dB SPL. Convert decibels re 1 µPa (dB re 1 µPa) to decibels SPL (dB SPL) below: type a value and the result updates as you type.
dB re 1 µPa to dB SPL calculator
Result
Decibel re 1 µPa (underwater) to Decibel SPL (re 20 µPa) conversion
1 dB re 1 µPa ≈ -25.02059991 dB SPLone decibel re 1 µPa in decibels SPL
1 dB SPL ≈ 27.02059991 dB re 1 µPaone decibel SPL in decibels re 1 µPa
Decibel re 1 µPa (underwater) (dB re 1 µPa): Sound pressure level in water and other media: 20 times the base-10 logarithm of the RMS sound pressure divided by the reference pressure of 1 µPa. The same sound reads about 26 dB higher than in dB SPL.
Decibel SPL (re 20 µPa) (dB SPL): Sound pressure level in air: 20 times the base-10 logarithm of the RMS sound pressure divided by the reference pressure of 20 µPa. 0 dB SPL is 20 µPa, about the quietest sound a young adult can hear.
Source:ISO 1683:2015, Acoustics: Preferred reference values for acoustical and vibratory levels
How to convert decibels re 1 µPa to decibels SPL
To convert decibels re 1 µPa to decibels SPL, subtract about 26.02059991 decibels.
Formula
dB SPL = dB re 1 µPa − 26.02059991
The factor is rounded here. The calculator uses the exact value.
Examples
- 0 dB re 1 µPa = 0 − 26.02059991 ≈ -26.02059991 dB SPL
- 120 dB re 1 µPa = 120 − 26.02059991 ≈ 93.97940009 dB SPL
- 180 dB re 1 µPa = 180 − 26.02059991 ≈ 153.9794001 dB SPL
Decibel re 1 µPa (underwater) to Decibel SPL (re 20 µPa) conversion table
| Decibel re 1 µPa (underwater) (dB re 1 µPa) | Decibel SPL (re 20 µPa) (dB SPL) |
|---|---|
| 0 dB re 1 µPa | -26.02059991 dB SPL |
| 20 dB re 1 µPa | -6.020599913 dB SPL |
| 40 dB re 1 µPa | 13.97940009 dB SPL |
| 60 dB re 1 µPa | 33.97940009 dB SPL |
| 80 dB re 1 µPa | 53.97940009 dB SPL |
| 100 dB re 1 µPa | 73.97940009 dB SPL |
| 120 dB re 1 µPa | 93.97940009 dB SPL |
| 140 dB re 1 µPa | 113.9794001 dB SPL |
| 160 dB re 1 µPa | 133.9794001 dB SPL |
| 180 dB re 1 µPa | 153.9794001 dB SPL |
| 200 dB re 1 µPa | 173.9794001 dB SPL |
Values rounded to 10 significant digits where needed.
Frequently asked questions
- What is 0 dB re 1 µPa in dB SPL?
- 0 dB re 1 µPa is about -26.02059991 dB SPL. To convert decibels re 1 µPa to decibels SPL, subtract about 26.02059991 decibels.
- How do I convert decibels SPL to decibels re 1 µPa?
- To convert decibels SPL to decibels re 1 µPa, add about 26.02059991 decibels. The formula is dB re 1 µPa = dB SPL + 26.02059991.
- Is this conversion exact?
- Yes. Both units have exact definitions, but the factor has more decimal places than can be shown, so displayed results are rounded. The calculator works with 50 significant digits before rounding.