How Loud Is a Lawn Mower? (Around 90 dB)
Quick answer
85–95 dB
A petrol lawn mower measures roughly 90 dB at the operator's ear. NIOSH guidance allows about two hours of unprotected exposure per day at that level, so hearing protection is sensible for anything longer than a small lawn.
60 dB (robot mower) to 95 dB (petrol ride-on)
measured at the operator's position
NIOSH guideline: about 2–2.5 hours per day at 90 dBA without protection.
30 dB
60 dB
85 dB
120 dB
How a lawn mower compares to other sounds
| Sound source | Decibel level | Relative loudness |
|---|---|---|
| Robot mower | 58–65 dB | |
| Battery/electric push mower | 75–82 dB | |
| Petrol push mower | 88–92 dB | |
| Petrol ride-on mower | 92–95 dB | |
| Leaf blower | 95–105 dB | |
| Mower heard from 15 m away | 65–70 dB |
Petrol versus electric: a real 10–15 dB difference
The combustion engine, not the blade, produces most of a mower's noise. Switching from petrol to battery typically removes 10–15 dB — which, on the logarithmic decibel scale, is roughly a halving to a quarter of perceived loudness and a tenfold reduction in sound energy.
Robot mowers sit around 60 dB, quiet enough to run in the evening in most neighbourhoods without triggering complaints.
How far the noise travels
In open air, sound drops about 6 dB every time the distance doubles. A 90 dB mower is roughly 84 dB at 2 m, 78 dB at 4 m, and about 66 dB at 16 m — still clearly audible inside a neighbour's home with the window open.
Fences and hedges scatter high frequencies but do very little for the low-frequency engine rumble that carries furthest.
When to wear hearing protection
NIOSH's recommended limit is 85 dBA for 8 hours, halving for every 3 dB: 88 dBA for 4 hours, 91 dBA for 2, 94 dBA for 1. These are occupational guidelines, not injury thresholds, but mowing a large garden with a petrol machine can exceed them.
- Under 30 minutes on a petrol mower: protection optional but recommended
- Over 1 hour on a petrol mower: earmuffs or plugs strongly recommended
- Ride-on mowers: always wear protection
- Add a leaf blower near 100 dBA and you can use up the daily recommended dose in about 15 minutes
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Start measuringFrequently asked questions
How many decibels is a lawn mower?
About 90 dB for a petrol push mower at the operator's ear, 75–82 dB for an electric model, and around 60 dB for a robot mower.
Do I need ear protection to mow the lawn?
For petrol mowers it is sensible for anything beyond a short session. At 90 dBA, NIOSH's guideline allows roughly two to two and a half hours of unprotected exposure per day.
What time can I legally mow the lawn?
Rules vary by municipality, but typical residential quiet hours run from 22:00 to 07:00 on weekdays with tighter limits on Sundays. Check your local noise ordinance.
Related sound levels
Sources
Exposure times follow NIOSH's occupational recommended exposure limit (85 dBA over 8 hours, 3 dB exchange rate). They are guidelines for limiting risk, not thresholds at which injury is certain.
Decibel figures on this page are typical published values and vary with distance, equipment, and environment. Readings from a phone or laptop microphone are estimates, not certified measurements.