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Generator Fit Guide
Will your generator fit? Measure it in two minutes, or send us the model and we will check.
The Generator Box fits most portable generators up to about 12,000 watts. Its outside dimensions are 42″ W × 33″ D × 30″ H. Before you order, spend two minutes measuring your generator it’s the one thing worth double-checking.
How to measure your generator
- Measure the full footprint. Length and width at the widest points, including the frame, the handles folded down, the wheels and any wheel kit. Wheel kits often add several inches of length.
- Measure the height from the ground to the highest point, usually the fuel cap, the handle or the roll cage.
- Leave room for air. The usable space inside is a little smaller than the outside dimensions, and the generator needs clearance around it so cooling air can move. If your measurements land within an inch of 42 × 33 × 30, treat it as a tight fit and call us first.
Fit examples
These are real-world examples with approximate manufacturer dimensions. Always measure your own unit, since wheel kits and accessories change the numbers.
| Generator class | Example model | Approx. size | Fit |
|---|---|---|---|
| Medium inverter (3,000–5,000W) | Westinghouse iGen5000 | 24.5″ L × 17.5″ W × 20″ H | Fits with room to spare |
| Large inverter (7,000–9,500W) | Predator 9500 | 31″ L × 23.75″ W × 28.87″ H | Fits (about 1″ clearance on top) |
| Open-frame (7,000W running / 9,000W starting) | Champion 9000W (shown in our photos) | Open frame with wheel kit | Fits |
| Large open-frame (7,500–12,000W) | DuroMax XP12000EH | 40″ L × 29″ W × 27.5″ H (with wheel kit) | Squeezes in — very tight fit |
Rules of thumb
- Inverter generators (3,000W–9,500W): almost always fit. Enclosed inverter bodies are compact and square.
- Open-frame generators (up to about 9,000W starting): generally fit. The Champion 9,000-watt unit shown in our photos sits inside with room to work around it.
- Large open-frame generators (10,000W–12,000W): possible but tight, especially with a wheel kit. Measure carefully.
- Over 12,000 watts, or a generator with a tall roll cage: ask us about a custom size. Microfab is a full-service sheet metal shop and can quote a larger enclosure.
Clearance and airflow
- Keep the side air windows fully open whenever the generator runs. They are the intake and exhaust path for cooling air.
- Add a small fan. We highly recommend running a small fan inside the enclosure to move air and keep the unit from overheating. It isn’t required, but it’s the cheapest insurance there is, especially on hot days or long outages.
- Don’t pack tools, fuel cans or covers into the empty space around the generator. That space is part of the airflow.
- Give the box itself room outdoors too: clear of shrubs, fences and snowbanks, with the exhaust pointed away from the house.
Not sure, or it's close?
Send us your generator’s make and model, or your own measurements, and we’ll tell you honestly whether it fits before you order. Call (203) 267-1000 or use the contact form.
Also worth knowing: the box is $1,295 plus $150 flat-rate FedEx shipping, weighs 85 lbs, locks with a standard padlock (not included) and bolts down through four base holes. Full specifications →
+ $150 flat-rate FedEx shipping
- .080" aluminum, white textured powder coat
- 42" W × 33" D × 30" H · 85 lbs
- Hinged lid + fold-out air windows
- Padlock-lockable, bolts to your pad