Last verified: October 1, 2026
Short answer: most air-cooled home standby generators are rated at about 61–67 dB(A) when running under load and about 55–57 dB(A) during the weekly self-test, according to their manufacturers. That is roughly between a normal conversation and a busy restaurant: clearly audible outdoors, but usually acceptable to neighbors when the unit is placed well and tested at a reasonable hour. Portable generators, especially conventional open-frame models, are often louder.
Published noise levels for popular models
| Generator | Weekly exercise | Normal operation |
|---|---|---|
| Generac Guardian 10 kW | 57 dB(A) | 61 dB(A) |
| Generac Guardian 14 kW | 55 dB(A) | 65 dB(A) |
| Generac Guardian 18–24 kW | 57 dB(A) | 67 dB(A) |
| Kohler 26RCAL (26 kW) | 56 dB(A) | 67 dB(A) |
| Champion 14 kW aXis | Not listed | 62 dB(A) |
Figures as published by each manufacturer: Generac Guardian Series brochure, Kohler’s 26RCAL product page and Champion’s 14 kW product page. Manufacturers don’t always measure in the same way or at the same distance, so treat differences of 1–2 dB with caution.
What these numbers mean for your ears
Decibels are a logarithmic scale. Two rules of thumb make them easier to read:
- About +10 dB sounds roughly twice as loud. So a generator at 67 dB(A) sounds noticeably louder than the same unit’s 57 dB(A) exercise mode.
- Distance helps. Outdoors, sound drops as you move away from the source, and a house wall between you and the generator blocks a large part of it.
In practice, homeowners describe a standby generator under load as a steady engine hum. Inside a closed house, with the unit on the far side, most people find it easy to sleep through.
How distance changes the number
A published decibel figure only means something together with the distance at which it was measured. Generac, for example, states the sound level of its 26 kW unit at 23 feet. Outdoors, in open space, sound from a compact source like a generator falls by about 6 dB every time the distance doubles. That rule lets you estimate what you or a neighbor will actually hear:
| Distance from the generator | Unit rated 67 dB(A) at 23 ft (normal operation) | Same unit in a 57 dB(A) exercise |
|---|---|---|
| About 12 ft | About 73 dB(A) | About 63 dB(A) |
| 23 ft | 67 dB(A) | 57 dB(A) |
| About 46 ft | About 61 dB(A) | About 51 dB(A) |
| About 92 ft | About 55 dB(A) | About 45 dB(A) |
These are open-field estimates. Real yards are not open fields: a house wall or a solid fence between the generator and the listener lowers the level further, while hard surfaces nearby, such as a wall right behind the unit or the corner between two walls, can reflect sound and raise it. Use the table to compare locations, not to predict an exact reading.
A placement example
Imagine two possible spots for the same unit. Spot A is beside the garage, 12 feet from the property line and about 25 feet from the neighbor’s bedroom window, with nothing in between. Spot B is behind the house, roughly 50 feet from that window, with the house itself blocking the direct line. During an outage, the neighbor would hear roughly the rated 67 dB(A) at Spot A, but at Spot B the doubled distance alone takes about 6 dB off before the house blocks a good part of what remains. The difference between the two spots is larger than the difference between any two brands in the table at the top of this page.
Spot B may need a longer gas line and wire run, which costs more (see Hidden Generator Installation Costs). Whether that is worth paying for depends on how close your neighbors are and how often you expect long outages. Ask your installer to price both locations so you can decide with real numbers.
Why the weekly test is quieter
Many standby generators run their automatic self-test at reduced engine speed. Generac calls this Quiet-Test and describes it as running at a lower RPM for a five- or twelve-minute test while using less fuel. That is why the exercise figure in the table is several decibels lower than the normal operating figure. You can choose the day and time of the test: a late-morning weekday slot keeps both you and your neighbors happy. See Generator Exercise Settings.
What makes a generator louder in real life
- Load: a unit near full load is louder than one at half load. Big appliances starting and stopping change the sound.
- Reflections: walls, fences and the corner between two walls can bounce sound toward a patio or a neighbor’s window.
- Exhaust direction: the exhaust side is the noisiest. Pointing it away from living areas matters.
- Vibration: a unit on an uneven or poor pad can transmit vibration.
- Enclosure condition: loose panels or worn parts rattle. If the sound changes, have it checked.
How to keep the noise down
- Placement: keep the unit away from bedroom windows, yours and the neighbors’, while respecting required clearances. See Standby Generator Placement.
- Use the house as a barrier: the side of the house away from patios and neighbors is usually the best spot.
- Screening: a fence or dense planting can soften sound and hide the unit, but must stay outside the 3-foot clearance and must not block airflow.
- Load management: keeping the generator away from full load also keeps it quieter. See Generator Load Management.
- Maintenance: a well-maintained engine and tight enclosure run more quietly.
Portable generators
Portable generators vary widely. Inverter models are generally the quietest because their engines slow down at light loads, while large conventional open-frame units are usually the loudest. They also have to run more than 20 feet from the house for carbon monoxide safety, which helps with noise inside but can mean they sit closer to a neighbor’s property. If noise matters, compare published dB(A) ratings and the load at which they were measured. See Inverter vs Conventional Generator.
Noise rules and neighbors
Some towns and homeowners associations set noise limits, quiet hours or property-line setbacks for equipment like generators. Emergency operation during an outage is often treated differently from routine testing, but rules vary. Check during the permit stage (see Do You Need a Permit?), and talk to your neighbors before installation. Showing them where the unit will go and when it will test usually avoids complaints.
How to compare noise between quotes
| Question | Why it matters |
|---|---|
| What is the published dB(A) in normal operation and in exercise? | You’ll hear the exercise weekly and the full-load figure during outages |
| At what distance was it measured? | Figures measured farther away look lower |
| Where will the unit sit relative to bedrooms and neighbors? | Placement often matters more than a few decibels |
| Which way will the exhaust face? | The exhaust side is the loudest |
Frequently asked questions
Can I build a sound enclosure around my generator?
Only with products the manufacturer approves. Home standby generators already have sound-attenuating enclosures and need free airflow and clearances; an improvised box can cause overheating and void the warranty.
Is 65 dB loud?
It is comparable to a lively conversation or background noise in a busy restaurant at close range. At the distance of a neighbor’s house, and with walls in between, it is much quieter.
Are bigger generators louder?
Not always. In Generac’s range, the 14 kW is rated at 65 dB(A) and the 18–24 kW units at 67 dB(A): only a small step. Placement and load usually matter more than size.
Bottom line
Expect a steady hum in the low-to-high 60s dB(A) during outages and a quieter weekly test. Choose the location carefully, point the exhaust away from people, schedule the test sensibly and keep the unit well maintained.