Convert Neper to Bel
Live bidirectional calculator for Nepers (Np) and Bels (B) with verified formula and conversion charts.
Sound Level3 units
How the Calculation Works (Linear Scaling)
Since 1 Bel = 1.151293 Nepers, divide the value in Nepers by 1.151293.
Neper to Bel Conversion Table
Precomputed values for quick reference and printing.
| Neper | Bel |
|---|---|
| 1 Np | 0.8686 B |
| 2 Np | 1.7372 B |
| 3 Np | 2.6058 B |
| 4 Np | 3.4744 B |
| 5 Np | 4.3429 B |
| 6 Np | 5.2115 B |
| 7 Np | 6.0801 B |
| 8 Np | 6.9487 B |
| 9 Np | 7.8173 B |
| 10 Np | 8.6859 B |
| 15 Np | 13.0288 B |
| 20 Np | 17.3718 B |
| 25 Np | 21.7147 B |
| 30 Np | 26.0577 B |
| 40 Np | 34.7436 B |
| 50 Np | 43.4294 B |
| 75 Np | 65.1442 B |
| 100 Np | 86.8589 B |
| Bel | Neper |
|---|---|
| 1 B | 1.1513 Np |
| 2 B | 2.3026 Np |
| 3 B | 3.4539 Np |
| 4 B | 4.6052 Np |
| 5 B | 5.7565 Np |
| 6 B | 6.9078 Np |
| 7 B | 8.059 Np |
| 8 B | 9.2103 Np |
| 9 B | 10.3616 Np |
| 10 B | 11.5129 Np |
| 15 B | 17.2694 Np |
| 20 B | 23.0259 Np |
| 25 B | 28.7823 Np |
| 30 B | 34.5388 Np |
| 40 B | 46.0517 Np |
| 50 B | 57.5646 Np |
| 75 B | 86.3469 Np |
| 100 B | 115.1293 Np |
About Neper (Np)
A logarithmic level ratio unit based on natural logarithms (base e). Under the international amplitude/field ratio convention (ISO 80000-3), 1 Np = ln(e) = 2 / ln(10) B โ 0.8685889638 B โ 8.685889638 dB.
History: Named after John Napier (1550โ1617), the inventor of logarithms. Retained in international standards (IEC and ITU) for natural logarithmic attenuation.
Common Uses: Transmission line exponential decay equations, acoustic wave damping coefficient analysis, filter attenuation.
About Bel (B)
A dimensionless logarithmic level ratio unit defined as the base-10 logarithm of a power ratio (L = logโโ(P/Pโ)). In sound level measurement, 1 bel represents a tenfold change in power ratio.
History: Named in 1928 by Bell Telephone Laboratories in honor of Alexander Graham Bell (1847โ1922).
Common Uses: Telecommunications transmission line attenuation, computer fan acoustic noise power emission specifications.
โ Frequently Asked Questions
How many Bels are in 1 Neper?
There are exactly 0.868589 Bels in 1 Neper (1 Np = 0.868589 B).
What is the formula to convert Neper to Bel?
The formula is: Bel = Neper / 1.151293. Since 1 Bel = 1.151293 Nepers, divide the value in Nepers by 1.151293.
How do I convert 1 Np to B manually?
To convert 1 Np to B: apply the formula Bel = Neper / 1.151293. Substituting gives: 1 / 1.151293 = 0.8686 B.