Tools/dB Calculator
dB Calculator
Convert between the decibel scales used in professional audio. Enter a value and select its unit — results appear instantly in all other scales.
Equivalent values
dBFS24.00
dBV-2.21
dBSPL94.00
dBm0.00
About these scales
dBFS
Digital Full Scale — 0 dBFS is the maximum level in a digital system. All values are zero or negative.
dBu
Referenced to 0.775 V RMS. Standard in professional balanced audio. 0 dBu ≈ +4 dBu nominal operating level.
dBV
Referenced to 1 V RMS. Common in consumer/semi-pro equipment. 0 dBu = −2.21 dBV.
dBSPL
Sound Pressure Level — referenced to 20 µPa, the threshold of human hearing. Acoustic measurement.
dBm
Power referenced to 1 mW into 600 Ω. Legacy unit from telephone engineering; 0 dBm = 0.775 V into 600 Ω.
Reference note: The dBFS → dBu conversion assumes the professional standard of 0 dBFS = +24 dBu. Consumer gear often uses 0 dBFS = +18 dBu. The dBSPL relationship is a rough acoustic reference — exact values depend on the transducer sensitivity.