Estimate sound power level, acoustic output, and free-field intensity. Review results, charts, exports, and examples. Make better noise decisions across engineering designs today confidently.
Use the mode selector for direct, reverse, or free-field noise calculations.
The graph shows free-field level decay with distance.
These example values help verify typical engineering noise magnitudes.
| Source | Approx. Sound Power Level | Approx. Acoustic Power | Typical Note |
|---|---|---|---|
| Small ventilation fan | 80 dB | 1.0000e-4 W | Common building service equipment. |
| Office air handler | 90 dB | 1.0000e-3 W | Moderate mechanical room source. |
| Portable compressor | 95 dB | 3.1623e-3 W | Typical construction support equipment. |
| Industrial blower | 100 dB | 1.0000e-2 W | High-output steady broadband source. |
| Large generator set | 110 dB | 1.0000e-1 W | Requires strong engineering controls. |
| Heavy stamping machine | 118 dB | 6.3096e-1 W | Impulsive industrial noise source. |
Lw = 10 log10(W / W0)
W = W0 × 10Lw / 10
I = (Q × W) / (4πr²)
L = Lw + 10 log10(Q / 4πr²)
Ltotal = 10 log10(Σ10Li/10)
These equations help convert between acoustic power, sound power level, radiation geometry, and combined engineering noise output.
Sound power level measures total acoustic energy emitted by a source. It describes the source itself, not the listening position. That makes it useful for comparing machines under consistent reference conditions.
Sound power belongs to the source. Sound pressure depends on location, distance, reflections, and room conditions. Two listeners can hear different sound pressure levels from the same sound power source.
That reference is the accepted standard for airborne acoustics. It provides a common base for decibel calculations and lets engineers compare equipment using the same benchmark.
Q adjusts for how sound radiates into space. A source near walls or floors often radiates into a smaller solid angle, increasing level in the exposed field direction.
Yes. Enter additional source levels as comma-separated values. The calculator converts each level to linear power, sums them, and converts the total back to decibels.
Only in ideal free-field conditions. Real rooms, barriers, reflections, absorption, and atmospheric effects can change actual decay. Use this page for engineering estimates, not full room simulation.
Use it during equipment comparison, procurement, enclosure design, noise control planning, and specification writing. It is especially useful when measurements must stay independent from room acoustics.
It is an engineering estimate based on ideal spreading assumptions. It works well for early calculations, but field measurements remain necessary for final compliance decisions.
This page uses a white theme and a single column layout. The calculator area uses three columns on large screens, two on smaller screens, and one on mobile devices. Results appear below the header and above the form after submission, as requested.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.