Calculators » Signal and Communication » Neper to dB Conversion: Formula and Calculator

Neper to dB Conversion: Formula and Calculator

neper decibel conversion formula calculator

The Neper (Np) is a logarithmic unit widely used in fields such as telecommunications, acoustics, and electrical engineering to express ratios of values like voltage or power. Understanding the Neper formula is crucial for accurately converting Nepers to decibels (dB), another prevalent logarithmic unit.

This page offers a comprehensive explanation of the Neper to decibel conversion formula, a step-by-step guide for converting Nepers to dB, and an easy-to-use Neper to dB calculator.

Relationship between Decibels and Nepers

Decibel (dB)

In microwave engineering, various measurements such as return loss, attenuation or insertion loss, and gain are expressed in decibels (dB). The decibel is a relative quantity and is expressed as a ratio of either two power levels or one power level with respect to one watt.

For an input power of P1 and an output power of P2, the power gain and voltage gain can be expressed as follows (unit: decibels):

G = 10 * Log (P2/P1) … dB
G = 20 * Log (V2/V1) … dB

Absolute power levels can be expressed with respect to a reference power in dB and dBm as follows:

Power (dB) = 10 * Log (P in watts / 1 watt) dB
Power (dBm) = 10 * Log (P in milli-watts / 1 mW) dBm

Neper

The Neper is the ratio of two power levels or two voltage levels taken in natural logarithms. It is expressed as follows and denoted as Np.

1 Np = ln (V1/V2) …Np (For voltage)
1 Np = (1/2) * ln (P1/P2) …Np (For power)
1 Np = 10*Log (e)² = 8.686 dB OR
1 dB = 0.115 Np

dB to Neper Conversion Calculator

EXAMPLE:

dB (Input) = 3 dB
Neper (Output) = 0.345 Np

dB to Neper Conversion Formula or Equation

The following equation or formula is used for the dB to neper conversion calculator.

dB to neper conversion-formula

Neper to dB Calculator

EXAMPLE:

Neper (Input) = 3 Np
dB (Output) = 26.058 dB