Convert any signal level between dBu, dBV, dBFS, volts RMS, peak and peak-to-peak. Pick your converter's 0 dBFS calibration to see digital headroom, and see how the level compares with +4 dBu professional and −10 dBV consumer line level.
Last updated:
dBu
Check your interface's spec sheet for 'maximum input/output level'.
Enter your values to see the result.
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How to use the Audio Level Converter
Enter a level and choose its unit (for example +4 and dBu).
Set 0 dBFS to your interface's maximum level so the dBFS figures match your gear.
Press Convert to see the level in every unit, plus headroom.
Check the comparison with pro and consumer line level and the reference table.
Copy the results or download the table.
Audio level formulas
Decibel voltage units compare a voltage V (RMS) to a fixed reference using 20 × log10(V ÷ reference):
Unit
Reference (0 dB)
From volts RMS
Back to volts RMS
dBu
0.7746 V RMS (√0.6)
20 × log10(V ÷ 0.7746)
0.7746 × 10^(dBu ÷ 20)
dBV
1 V RMS
20 × log10(V)
10^(dBV ÷ 20)
dBFS
Digital full scale
dBu − (dBu at 0 dBFS)
Convert dBu as above
dBm (600 Ω)
1 mW
10 × log10(V² ÷ 600 ÷ 0.001)
Same as dBu into 600 Ω
Worked example: a mixer output reads −16 dBFS on an interface calibrated so that 0 dBFS = +22 dBu. The analog level is −16 + 22 = +6 dBu. In volts: 0.7746 × 10^(6 ÷ 20) = 1.546 V RMS, and in dBV: 6 − 2.218 = +3.78 dBV. As a sine wave that is 4.37 V peak-to-peak.
Common reference levels
Level
dBu
dBV
Volts RMS
Volts p-p (sine)
dBFS at +24 dBu cal.
Typical dynamic microphone (about 2 mV)
-51.76
-53.98
2.00 mV
0.006 V
-75.8
Consumer line level, −10 dBV
-7.78
-10.00
0.316 V
0.894 V
-31.8
0 dBu reference
+0.00
-2.22
0.775 V
2.191 V
-24.0
0 dBV reference
+2.22
+0.00
1.000 V
2.828 V
-21.8
Pro line level, +4 dBu
+4.00
+1.78
1.228 V
3.472 V
-20.0
Consumer DAC / CD player, 2 V RMS
+8.24
+6.02
2.000 V
5.657 V
-15.8
EBU full scale, +18 dBu
+18.00
+15.78
6.153 V
17.403 V
-6.0
SMPTE full scale, +24 dBu
+24.00
+21.78
12.277 V
34.723 V
+0.0
Tips for matching levels between gear
Pro into consumer: a +4 dBu output feeding a −10 dBV input is about 11.8 dB too hot. Turn the source down or use a pad so the input does not clip.
Consumer into pro: a −10 dBV source into a +4 dBu input is quiet, costing about 12 dB of signal-to-noise unless you add gain.
Know your 0 dBFS: interfaces differ (often +18 to +24 dBu). Look for "maximum input level" in the specs and enter it so dBFS headroom figures are realistic.
Meters read differently: VU meters show averaged RMS, peak meters show instantaneous peaks. A sine wave peaks 3 dB above its RMS level; music often peaks 10–20 dB higher.
Frequently asked questions
What is the difference between dBu and dBV?
Both express voltage in decibels but use different references: 0 dBu = 0.7746 V RMS and 0 dBV = 1 V RMS. So dBu is always 2.218 dB higher than dBV for the same voltage (dBu = dBV + 2.218).
How do I convert +4 dBu to dBV?
Subtract 2.218: +4 dBu = +1.78 dBV, which is 1.228 V RMS.
What is the difference between +4 dBu and −10 dBV?
+4 dBu (1.228 V RMS) is professional line level and −10 dBV (0.316 V RMS, or −7.78 dBu) is consumer line level. The difference is about 11.8 dB, roughly four times the voltage.
How do I convert dBFS to dBu?
Add your converter's calibration level: dBu = dBFS + (the dBu that equals 0 dBFS). With the common +24 dBu calibration, −20 dBFS = +4 dBu; with the EBU +18 dBu calibration, −18 dBFS = 0 dBu.
How do I convert volts RMS to peak-to-peak?
For a sine wave, multiply RMS by 2√2 (about 2.828). 1 V RMS is 1.414 V peak and 2.828 V peak-to-peak. Other waveforms have different ratios.
Is dBu the same as dBm?
Only into a 600 Ω load. dBm measures power relative to 1 mW, and 0.7746 V across 600 Ω dissipates exactly 1 mW, which is where the 0.7746 V dBu reference comes from. Modern equipment rarely uses 600 Ω loads, so dBu is preferred.
Can a dBFS value be positive?
No. 0 dBFS is the largest value a fixed-point digital system can represent, so all real levels are 0 dBFS or below. A signal that would exceed it clips.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.