Estimate fan noise after speed, airflow, distance, enclosure, duct attenuation, vibration, and room adjustments. This calculator can help compare fan speed changes, estimate final sound level, and identify whether a fan may be quiet, noticeable, or intrusive.
Base fan noise:
Enter the measured or rated fan sound level at a known reference speed and distance.
Speed change:
The calculator estimates the sound change from changing RPM or percent speed.
Noise adjustments:
Distance, enclosure reduction, duct attenuation, vibration, and room effects are applied to estimate the final fan noise level.
A fan noise calculator helps estimate how loud an axial fan, inline duct fan, exhaust fan, centrifugal fan, computer fan, or HVAC fan may be after speed changes and noise-control adjustments.
This is a simplified estimate. Real fan noise depends on fan curve, blade design, airflow restriction, turbulence, motor tone, bearing condition, mounting, vibration, ductwork, and room acoustics.
This calculator uses simplified fan noise and distance estimates:
Start with a fan sound level, adjust for fan speed change, subtract distance and noise-control reductions, then add vibration or room penalties.
Yes. Lowering fan speed can significantly reduce noise, especially when turbulence, blade noise, or motor noise are tied to speed.
Common causes include high RPM, dirty blades, restrictive airflow, worn bearings, loose mounting, vibration, rattles, unbalanced blades, or noisy grilles and ducts.
Common fixes include lowering speed, cleaning blades, improving airflow, using isolation mounts, tightening loose parts, replacing bearings, adding duct silencers, or using a larger quieter fan.