Le dB ↔ Percentage Calculator helps users quickly convert decibels (dB) to percentage and vice versa. Decibels represent a échelle logarithmique couramment utilisé dans audio engineering, telecommunications, signal processing, and physics to measure changes in power, voltage, current, or amplitude.
Since decibels are non linéaire, converting them into a percentage requires logarithmic calculations. This calculator simplifies these conversions, making it easier to understand signal gains, losses, and power changes.
Formula for Db ↔ Percentage Calculator
1. Convert dB to Percentage
For Power Gain/Loss:
Since decibels measure a logarithmic change in power, the percentage change is calculated as:
Percentage Change (%) = (10^(dB / 10) – 1) × 100
For Voltage, Current, or Amplitude Gain/Loss:
When measuring voltage, current, or amplitude changes, the formula is:
Percentage Change (%) = (10^(dB / 20) – 1) × 100
2. Convert Percentage to dB
For Power Change:
Pour trouver le décibel change from a percentage increase or decrease in power:
dB = 10 × log10(1 + (Percentage / 100))
For Voltage, Current, or Amplitude Change:
For voltage, current, or amplitude percentage change:
dB = 20 × log10(1 + (Percentage / 100))
Reference Table – Common dB to Percentage Conversions
To make conversions easier, here is a pre-calculated reference table for commonly used dB values:
| Décibels (dB) | Power Change (%) | Voltage/Amplitude Change (%) |
|---|---|---|
| -20 DB | -99% | -90% |
| -10 DB | -90% | -68% |
| -6 DB | -75% | -50% |
| -3 DB | -50% | -29% |
| 0 dB | 0% | 0% |
| + 3 dB | + 100% | + 41% |
| + 6 dB | + 300% | + 100% |
| + 10 dB | + 900% | + 216% |
| + 20 dB | + 9900% | + 900% |
This table allows audio engineers, sound technicians, and electronics professionals to quickly estimate signal strength changes without manually calculating.
Example of Db ↔ Percentage Calculator
1. Convert +6 dB to Percentage (Voltage Gain)
Using the voltage formula:
Percentage Change (%) = (10^(6 / 20) – 1) × 100
Percentage Change (%) ≈ (2 – 1) × 100 ≈ % D'augmentation 100
Cela signifie un +6 dB gain doubles the voltage or amplitude.
2. Convert 50% Power Increase to dB
Using the power formula:
dB = 10 × log10(1 + (50 / 100))
dB = 10 × log10(1.5) ≈ 1.76 dB
Cela signifie un 50% power increase corresponds to approximately +1.76 dB.
FAQ les plus courantes
Decibels provide a échelle logarithmique, which makes it easier to express large variations in power, signal strength, and intensity. A small dB change can represent a large percentage change, making it ideal for fields like audio processing and telecommunications.
Power uses a facteur de 10, while voltage and amplitude use a facteur de 20 in logarithmic calculations. This is because power is proportional to the square of voltage.
Oui! Negative dB values représenter un loss in power or amplitude, meaning the signal strength is decreasing compared to the reference level.