Short answer: For good sleep, a bedroom should average about 30 dB(A) with single noises staying below 45 dB, the levels in the WHO Guidelines for Community Noise. A steady 40 dB is quiet enough for most people; 50 dB or more can disturb sleep. Keep a white noise machine well below 50 dB(A) at a baby’s cot, and around 40–50 dB for adults.
Noise at night doesn’t have to wake you to affect you: it can shift you into lighter sleep and raise your heart rate. This guide gives the World Health Organization night-time levels, what 30, 40 and 50 dB mean in a real bedroom, how loud a white noise machine should be, and practical ways to make a bedroom quieter. You can check your own room with our free sound decibel meter in a few minutes.
WHO Noise Guidelines for Sleep
| Guideline | Level | What it means |
|---|---|---|
| WHO 1999, inside the bedroom | 30 dB(A) LAeq | Average level over the night for continuous noise |
| WHO 1999, single events indoors | Below 45 dB LAmax | Avoid noise events above this more than about 10–15 times a night |
| WHO 1999, outside the bedroom window | 45 dB(A) LAeq | So people can sleep with the window partly open |
| WHO 2009 Night Noise Guidelines for Europe | 40 dB Lnight, outside | Year-round average at the façade |
| WHO 2018 Environmental Noise Guidelines | Road traffic below 45 dB Lnight | Railway 44 dB, aircraft 40 dB |
The indoor numbers are the ones you can check yourself. LAeq is the energy average and LAmax is the loudest moment, both A-weighted to match the ear (see dB vs dBA). The outdoor Lnight figures are yearly averages used for planning roads and airports, not something one night’s measurement proves.
How Many Decibels Is Good for Sleeping?
| Bedroom level | Typical situation | Effect on sleep |
|---|---|---|
| 20–30 dB(A) | Quiet rural bedroom at night | Ideal; most people sleep undisturbed |
| 30–40 dB(A) | Suburban bedroom, quiet fridge or distant traffic | Fine for most people; light sleepers may notice changes |
| 40–45 dB(A) | Air conditioner, city bedroom with windows shut | Some awakenings from peaks above this |
| 45–50 dB(A) | Open window on a busy street, loud fan | Sleep disturbance is likely for many people |
| 55 dB(A) and above | Traffic noise in a front bedroom, a neighbour’s TV | Frequent disturbance; above the WHO night targets |
Steady noise is easier to sleep through than sudden changes. A 35 dB room with a motorbike passing at 60 dB can be worse than a steady 42 dB fan. For the daytime side of the scale, see typical room noise levels and the decibel chart.
Is 40 dB or 50 dB Too Loud to Sleep?
40 dB is about the level of a quiet library or a gentle fridge hum. As a steady background it is above the WHO 30 dB ideal but quiet enough for most people. 50 dB is like moderate rain or a loud fan. It is 10 dB higher, so it has ten times the energy and sounds about twice as loud (why is explained in the logarithmic decibel scale). Many people find 50 dB disturbing, especially if it varies. A 60 dB noise, such as normal conversation, will wake most sleepers.
How Loud Should a White Noise Machine Be?
White, pink or brown noise works by masking: a steady sound makes short changes, such as a car door, stand out less. It only needs to be loud enough to cover the peaks.
- For babies: keep the level well below 50 dB(A) at the cot. A 2014 study in Pediatrics tested infant sleep machines at maximum volume and found that, close up, they could easily exceed the 50 dB(A) limit recommended for hospital nurseries, some by a wide margin. Place the machine across the room, not on the cot, and use a low volume. Our baby room noise level guide has more.
- For adults: around 40–50 dB(A) at the pillow is commonly suggested. Start low and turn it up only until the disturbing sound fades into the background.
- Check it: measure at the pillow or cot for a minute. To hear the difference between colours of noise at a controlled level, try the tone generator.
How to Measure Your Bedroom at Night
One quick reading at bedtime won’t show what wakes you at 3 a.m. Put a phone or laptop on the bedside table, plugged in, with the microphone uncovered, and run the noise monitor overnight. It logs the average (Leq), the background (L90) and every loud event with its time. Next morning you’ll see whether the trouble is steady noise or a few sharp peaks, which need different fixes.
For better accuracy, calibrate the microphone first. Phone microphones have a noise floor of roughly 30–35 dB, so a very quiet bedroom may read a little high. A low hum from a boiler or a neighbour’s bass is easiest to identify with the frequency analyzer, and the background noise test flags mains hum. Our guide on how to measure decibels covers placement.
How to Make a Bedroom Quieter
- Earplugs: foam earplugs are cheap and effective, although real-world reduction is usually well below the number printed on the packet. Roll them thin and let them expand fully in the ear canal.
- Windows: an open window lets in most outside noise and typically cuts only about 10–15 dB; closed double glazing cuts roughly 25–35 dB. Sealing gaps around the frame helps as much as the glass.
- Soft furnishings: heavy curtains, rugs and upholstered furniture reduce echo and take the edge off high-pitched noise, but they won’t stop low-frequency traffic rumble.
- Room choice: a bedroom at the back of the house, away from the road, can be 10 dB or more quieter.
- Appliances: move chargers with coil whine, fridges and fans out of the bedroom, or put them on timers.
Every 3 dB you remove halves the sound energy, and two equal noise sources together add 3 dB; the decibel calculator does the sums. If the noise comes from next door, the apartment noise complaint guide explains the levels councils and landlords look for.
Noise, Sleep and Health
Long-term night noise is linked with poorer sleep, daytime tiredness and, over many years, higher cardiovascular risk, which is why WHO sets night limits. Bedroom levels are far below those that damage hearing (see the safe noise levels chart), but a very loud white noise machine used all night close to the ear is best avoided. If you snore, wake often or feel tired despite a quiet room, talk to a doctor. If you notice ringing at night, the online hearing test is a useful first screen before seeing an audiologist.
Frequently Asked Questions
What dB is good for sleeping?
About 30 dB(A) on average, with individual noises below 45 dB, following the WHO bedroom guideline.
Is 50 dB loud at night?
For a bedroom, yes. It is 20 dB above the WHO guideline and likely to disturb light sleepers, especially if it isn’t steady.
Is 35 dB quiet enough for sleep?
Yes, for nearly everyone. It is close to the WHO 30 dB(A) guideline.
How loud should white noise be for a baby?
Well below 50 dB(A) measured at the cot, with the machine placed away from the baby.
Does a fan count as white noise?
Yes. A steady fan masks peaks in the same way; measure it at the pillow and keep it to a comfortable level.
Addito is an audio analysis and sound measurement writer specializing in decibel testing, noise level analysis, sound frequency measurement, and audio engineering tools for creators, audio professionals, students, and everyday users. He creates practical content focused on sound measurement, hearing safety, microphone testing, and acoustic analysis tools.