Dishwasher decibel ratings: how quiet is quiet enough?

Dishwasher brochures quote noise levels in decibels (dBA), and the difference between models can look tiny: 42 dBA here, 48 dBA there. In practice those few numbers matter a lot, especially in an open-plan kitchen. Here is how to read the ratings.

How decibels work

The decibel scale is logarithmic. An increase of about 10 dB is generally perceived as roughly twice as loud, and a difference of 3 dB is noticeable. So a 44 dBA dishwasher sounds clearly quieter than a 50 dBA one, not just slightly.

Typical ranges

Under 40 dBA	Very quiet; many owners rely on an indicator light to know it is running.
40 – 44 dBA	Quiet; suitable for open-plan kitchens and late-night running.
45 – 49 dBA	Moderate; noticeable in a quiet room but easy to talk over.
50 dBA and above	Clearly audible; typical of entry-level models.

What makes a dishwasher quieter

• Insulation around the tub and under the countertop.
• Stainless steel tubs tend to absorb more sound than plastic tubs.
• Brushless or inverter motors that run smoothly at variable speed.
• Toe-kick design — a full-length kick plate reduces noise escaping at floor level.

Ratings are measured in a lab

Manufacturers measure noise under standard conditions. In your kitchen, hard floors, an open space and a disposal running during drain all make a dishwasher seem louder. Installation matters too: a dishwasher that is not secured to the countertop or not level can vibrate.

Balancing noise with efficiency

Quiet models are often also efficient, because the same engineering that reduces noise reduces wasted energy. The ENERGY STAR dishwasher guide compares certified models. If you are choosing between brands, see our reliable appliance brands guide, and for a specific model, our Bosch SMS25EW00GB guide.