Engineering dB to Linear Calculator

Convert decibels into linear ratios for practical engineering tasks. Switch modes and validate results visually. Download outputs, examples, and charts for easier project documentation.

Calculator Form

Use the responsive calculator grid below. It shows three columns on large screens, two on smaller screens, and one on mobile.

Engineering Tool

Input value in dB

Enter positive, zero, or negative decibel values.

Conversion mode

Power uses dB/10. Amplitude uses dB/20.

Decimal precision

Controls numeric formatting for outputs.

Reference value

The linear ratio multiplies this value.

Reference unit label

Examples: W, V, A, Pa, unit.

Graph minimum dB

Start of the chart range.

Graph maximum dB

End of the chart range.

Graph step size

Smaller steps create denser curves.

Quick example presets

Click a preset, then calculate.

Formula Used

Power ratio conversion

dB = 10 × log10(P2 / P1)

Linear power ratio = 10^(dB / 10)

Amplitude, voltage, or current conversion

dB = 20 × log10(A2 / A1)

Linear amplitude ratio = 10^(dB / 20)

Scaled output formula

Scaled output = Reference value × Linear ratio

Percentage change = (Linear ratio − 1) × 100

How to Use This Calculator

Enter the decibel value you want to convert.
Select Power ratio mode for power-related calculations.
Select Amplitude / Voltage / Current mode for field quantities.
Set the reference value if you want a scaled engineering result.
Choose the numeric precision that fits your report or design note.
Adjust graph minimum, maximum, and step for the visual range.
Press Calculate to show results above the form.
Use the CSV or PDF buttons to export the result block.

Example Data Table

These reference values help compare power-ratio and amplitude-ratio interpretations at common decibel levels.

dB	Power Ratio	Amplitude Ratio
-30	0.001	0.031623
-20	0.01	0.1
-10	0.1	0.316228
-3	0.501187	0.707946
0	1	1
3	1.995262	1.412538
10	10	3.162278
20	100	10
30	1,000	31.622777

Frequently Asked Questions

1) What does dB to linear mean?

It converts a logarithmic decibel value into a direct multiplication ratio. The result tells you how many times larger or smaller a quantity is compared with its reference.

2) Why are there two formulas?

Power quantities use 10 in the divisor, while amplitude-like quantities use 20. That difference exists because power is proportional to the square of amplitude in many engineering systems.

3) When should I use power mode?

Use power mode for quantities such as power gain, power loss, intensity, and energy-related comparisons where the decibel definition is based on 10 × log10 of a ratio.

4) When should I use amplitude mode?

Use amplitude mode for voltage, current, pressure, and field-like measurements when the decibel relationship is based on 20 × log10 of a ratio.

5) What does 0 dB become in linear form?

Zero decibels always converts to a linear ratio of 1. That means the measured quantity is equal to the reference, with no gain and no attenuation.

6) Why does a negative dB value still produce a positive ratio?

The exponential inverse always returns a positive ratio. Negative dB simply means the linear result is less than 1, indicating attenuation relative to the reference.

7) What is the reference value used for?

The reference value lets you scale the pure ratio into a real engineering quantity. For example, a ratio can be multiplied by 5 V, 2 W, or 1 A.

8) Can I export the result for reports?

Yes. After calculation, use the CSV button for spreadsheet-friendly output or the PDF button for a portable report snapshot of the result details.