How to Measure Appliance Noise at Home
You bought a dishwasher rated at 44 dB. It sounds louder than that. You want to measure it yourself. Good instinct — but the number you get will depend heavily on how you measure. Here’s how to do it right, and what to expect.
Your three options
Smartphone apps (free, decent)
The best free option is the NIOSH Sound Level Meter app from the CDC. It’s been tested against calibrated lab equipment and lands within ±2 dBA of reference devices. That’s good enough for home use. It supports A-weighting, logs data over time, and was built by actual noise researchers. The catch: it’s iOS only. NIOSH has stated they can’t verify accuracy on Android due to hardware fragmentation across devices.
On Android, Decibel X is the most popular alternative. It’s pre-calibrated and supports both dBA and dBC weighting. Studies show it tends to underestimate noise levels by a few dB, which means your dishwasher might actually be louder than the app says. Not ideal for occupational safety, but fine for comparing appliances at home.
Both apps are useless below about 40 dBA. Phone microphones are MEMS (micro-electromechanical systems) — cheap, small, and not designed for precision acoustics. They clip at high levels and lose accuracy at low levels. For a 46 dB dishwasher in a quiet kitchen, you’re right at the edge of what a phone can reliably measure.
Cheap handheld SPL meters ($20–$50)
Devices like the TopTes TS-501B or similar meters on Amazon claim ±1.5 dB accuracy and measure down to 30 dBA. That’s better range than a phone, but “±1.5 dB” is the best-case figure. Real-world accuracy on cheap meters can be worse, especially at frequencies below 200 Hz or above 4 kHz — exactly where appliance motors and pumps live.
These are not certified Class 2 instruments. True Class 2 (IEC 61672) meters start around $100–$200. Below that, you’re buying consumer electronics with a microphone, not a calibrated measurement tool. That said, they’re consistent enough for relative comparison: measure your dishwasher, measure your fridge, compare the numbers. The absolute values might be off, but the ranking will be right.
Professional equipment ($200+)
A Class 2 sound level meter from a brand like Svantek, Larson Davis, or even a mid-range UNI-T will give you ±1 dB across the full frequency range, proper calibration, and data logging. If you’re measuring because you have a noise dispute with a landlord or neighbor, this is what you need — app measurements don’t hold up as evidence.
For most people reading this site: skip this tier. You’re choosing between appliances, not filing a lawsuit.
How to get consistent readings
The number you get depends almost entirely on technique. A sloppy measurement can be off by 10 dB, which is the difference between “barely audible” and “clearly annoying.”
Distance matters more than anything else
Sound drops roughly 6 dB every time you double the distance from the source. Measure your dishwasher at 0.5 meters and you’ll get a number 6 dB higher than at 1 meter. Manufacturer specs are typically measured at 1 meter, though many don’t state their test distance at all.
Pick one distance — 1 meter is the standard — and use it for everything. Hold the meter at the same height as the appliance, pointed toward it. Don’t measure from above or below.
Kill the background noise
Your measurement captures everything the microphone hears, not just the appliance. A refrigerator humming in the next room, street noise through a window, an HVAC system running — all of it gets added to your reading.
The practical test: measure with the appliance off. If your background noise is 35 dBA and the appliance measures 40 dBA, only about 5 dB of that reading is actually the appliance. You need at least 10 dB between background and source for a reliable measurement. If your kitchen is already at 42 dBA from ambient noise, you physically cannot get an accurate reading of a 44 dB dishwasher.
Close windows. Turn off other appliances. Measure late at night when traffic is minimal. Or accept that your measurement includes background noise and note it.
Use A-weighting
Both apps and meters offer weighting options: A, C, and sometimes Z (flat). Use A-weighting (dBA). It filters the signal to match how human ears perceive sound — rolling off low frequencies and very high frequencies that we’re less sensitive to. This is what manufacturers use, what noise regulations reference, and what makes numbers comparable.
C-weighting captures more low-frequency content and is useful for bass-heavy noise sources, but for home appliances, dBA is the standard.
Use slow time weighting
Most meters offer “fast” (125ms response) and “slow” (1 second response) settings. Slow averages out brief fluctuations and gives you a more stable, readable number. Use slow for appliances. Fast is for measuring impacts or other short-duration sounds.
Why your number won’t match the spec sheet
Expect a 3–8 dB discrepancy between your home measurement and the manufacturer’s published spec. This isn’t because anyone is lying (usually). The reasons are structural:
Different acoustic environments. Manufacturers measure in semi-anechoic chambers or standardized test rooms with controlled reflections. Your kitchen has hard countertops, tile floors, and parallel walls — all of which reflect sound and increase the reading. A reflective room can add 3–6 dB to a measurement compared to a treated test space.
Different operating phases. That 44 dB spec probably refers to the main wash cycle. The drain pump, the water fill, and the dry cycle are all louder. If you happen to measure during a drain cycle, you’ll get a higher number.
Installation variables. A dishwasher vibrating against poorly shimmed cabinetry sounds different from the same unit in a test jig. A washing machine on a flexible floor amplifies low-frequency vibration that wouldn’t exist on the concrete slab in a test lab.
Measurement uncertainty. Your phone or $30 meter has ±2–3 dB of uncertainty. The manufacturer’s lab equipment has ±0.5 dB. Even if everything else were equal, the numbers wouldn’t match exactly.
None of this means measuring at home is pointless. It means you should use your measurements for comparison, not as absolute verdicts. Measure the old dishwasher before it leaves. Measure the new one the same way. The delta between them is meaningful even if neither number matches a spec sheet.
Common mistakes
Measuring during the wrong cycle. Run the appliance through its full cycle and note the range. A dishwasher might read 42 dBA during wash and 55 dBA during drain. Both numbers are real.
Holding the phone against the appliance. Contact measurement picks up vibration, not airborne sound. Hold the phone or meter 1 meter away in open air.
Measuring once. Take at least three readings across different cycles and average them. Single measurements are noisy (no pun intended).
Ignoring reflections. Measuring in a corner or alcove inflates the number. Measure in the most open space available near the appliance.
Comparing across different setups. Your kitchen reading and your neighbor’s kitchen reading are not comparable, even for the same appliance model. Too many variables differ.
When to trust your ears vs. the meter
If the meter says 42 dBA but the sound drives you crazy, the meter is wrong about what matters. Human annoyance depends on frequency content, tonal character, and intermittency — none of which a single dBA number captures. A steady 45 dBA hum is less annoying than a 40 dBA whine with a sharp tonal peak at 2 kHz.
The meter tells you how loud. Your ears tell you how annoying. Both are valid data. If you’re choosing between two appliances and one measures louder but sounds less bothersome, trust your ears. The best appliance is the one you stop noticing.
For a quick reference on what different dB levels actually sound like, check the decibel chart. See how we evaluate noise data for our scoring approach.