Generator Buying Guide

During a power outage, a generator can keep your essential systems running—from lights, appliances, and heating to air conditioning, sump pumps, and WiFi. It can also protect your finances by preventing food spoilage and basement flooding. For individuals who rely on electrically powered medical equipment, a generator can be a literal lifesaver.

As power outages become more frequent and prolonged across the U.S., generators are becoming a vital layer of home protection. According to the U.S. Energy Information Administration, consumers faced an average of 11 hours of power interruptions in 2024, which is nearly double the amount recorded a decade ago. Major storms were responsible for the vast majority of these incidents.

While a generator can sustain your home during severe weather, it can also present significant risks if you fail to take precautions or set up the unit before a storm arrives. If you are working by flashlight or rushing to prepare, you might overlook critical safety steps when connecting the generator to your appliances or electrical panel.

To ensure your safety, always operate your generator outdoors, at least 20 feet away from your home, with the exhaust pointed away from the building. Before starting the unit, verify that your home has functional carbon monoxide (CO) detectors to help prevent poisoning. Ensure you purchase detectors that are UL 2034 certified or ETL listed, and exercise caution when buying these devices through third-party online marketplaces. You can find reliable options in our free ratings of CO detectors.

We also recommend utilizing low-level CO detectors, which are especially important for protecting children, the elderly, pregnant women, and those with preexisting health conditions. The Centers for Disease Control and Prevention provides additional information regarding carbon monoxide poisoning and prevention strategies.

Even if your generator features a built-in sensor that triggers an automatic shutdown when CO reaches dangerous levels in an enclosed space, we strongly advise you to adhere to the safety guidelines provided here.

Selecting the right home generator begins with determining your specific power requirements. Generators are categorized by their power output, which is measured in watts. This output dictates how many electronics and appliances you can operate simultaneously. A typical household requires roughly 5,000 watts to run several major appliances and window air conditioning units. However, you will likely need a higher capacity to power a full heating and cooling system or high-demand appliances like electric ovens or dryers.

Before reviewing our generator ratings to find the best model for your home, create a list of the devices you will need during an outage. Then, calculate the total wattage to ensure you are looking at the correct size.

Here are some rough wattage estimates for common essentials as you build out your list:

When purchasing a generator, you have four primary options to consider: home standby generators, portable generators, inverter generators, and portable power stations.

Home standby generators, often called whole-house generators, are permanently installed on your property. These units can run on propane or natural gas and activate automatically when the power goes out.

They are significantly more expensive than other options and must be installed by a professional electrician who can assist with municipal permits, noise ordinances, and proper placement. Installation costs often exceed the price of the generator itself, sometimes by several times.

Home standby generators start automatically during an outage and typically provide more power than the other three categories.

Many units perform a brief automatic test run daily to ensure they are ready for an emergency. They also conduct self-diagnostics to alert you or your dealer when maintenance is required.

You have a choice of fuel: propane, which is safer to store than the gasoline required for other models, or natural gas, which offers an unlimited fuel supply.

Whole-house generators, much like portable versions, carry a risk of carbon monoxide poisoning. Always ensure you have functional CO detectors installed in your home.

Roughly 5,000 to 20,000 watts. Because the installation costs for a smaller unit are similar to those for a larger one, it is usually practical to purchase a model that can easily handle your home’s power needs now and in the future.

$3,500 to $7,000 before installation, which can more than double the total expense.

Home Standby Generators Ratings

Portable generators are designed to be moved. Some are compact enough for tailgating, while others are better suited as a stationary backup power

These units are generally more affordable than home standby models, and there are no installation costs unless you choose to connect one to your home’s electrical panel.

Portable generators usually run on gasoline, which you may need to store in large quantities. If you store the unit for an extended period, you must add a stabilizer to the fuel to prevent it from clogging the system, which is why some generators fail to start after sitting idle for months.

A few models can run on both gasoline and liquid propane. Using propane is cleaner, preventing fuel residue from clogging the generator’s carburetor.

You can use portable generators anywhere on or off your property, but never in an enclosed space. Like a car engine, these models can quickly generate lethal levels of carbon monoxide. Always operate a portable generator at least 20 feet from your home and any equipment like window AC units or central air condensers, and direct the exhaust away from your house or any neighboring structures.

If it is raining, protect your generator with a canopy specifically designed for your model.

Some models feature electric starting. Note that the battery required for this feature may not be included.

The models we test provide 3,000 to 8,500 watts.

$400 to $2,000.

Like portable generators, inverter generators are mobile. They are significantly quieter because they adjust their engine speed to match the power demand rather than running at full capacity constantly. They also feature more advanced exhaust systems to reduce noise. However, inverter generators typically cost more than portable generators with similar power outputs.

Inverter generators are more efficient, allowing for longer run times on the same amount of gasoline. They also produce fewer emissions than standard portable generators, though you must still follow the same safety protocols to avoid carbon monoxide poisoning.

Sizes vary significantly, ranging from large inverter generators that can power an entire house—producing 5,000 watts or more and weighing over 250 pounds—to small, 30-pound versions ideal for camping.

The models we test provide 900 to 7,600 watts.

$300 to $5,000.

Portable power stations are large, rechargeable lithium-ion batteries that store electricity for later use. While they have limitations, they are the onlya generator outdoors

You charge the unit by plugging it into a wall outlet or using an included solar panel, though the latter method is quite slow.

Similar to a small inverter generator, a portable power station is best for short-term outages lasting hours rather than days, and they are excellent for camping or tailgating. These units do not provide as much power for as long as a portable generator and require periodic recharging. Solar panels can help extend the battery life.

Because they lack an engine, these devices are extremely quiet. They produce no fuel emissions or carbon monoxide, making them safe for indoor use. There are no starting issues because there is no engine to ignite. Think of them as a massive version of a portable phone charger. However, they tend to be heavier and significantly more expensive than a generator of comparable capacity.

The models we test provide 1,500 to 3,600 watts.

$500 to $2,500.

Portable Power Stations Ratings

Do not let wind, snow, or rain leave you in the dark. Look for these features to ensure your generator is as reliable, safe, and suited to your needs as possible.

This vital safety feature automatically kills the engine if a built-in sensor detects that carbon monoxide has reached dangerous levels. We have over a dozen generators in our ratings that include a CO safety shutoff. (We only recommend portable generators that include this feature.)

From Honda to Generac, more brands than ever offer this technology. You might see it marketed under terms like “CO Guard” or “CO Protect.” However, the only way to confirm a generator meets one of the two primary standards is to look for these certifications on the packaging:

ANSI/UL2201 Certified for Carbon Monoxide Safety

ANSI/PGMA G300 Certified Safety & Performance

Brands such as Echo and Ryobi are utilizing low-CO engines to help mitigate the risk of carbon monoxide poisoning.

When the power fails, the generator starts automatically without any manual intervention. This is ideal if you travel frequently or work far from home and cannot return quickly during an emergency.

Many portable models offer electric start, a push-button alternative to the frustration of pull-starting an engine. If the battery is not included, be sure to account for the additional cost of about $50. Stationary models come with automatic starting.

Some portable generators are designed to run on a natural gas line or a propane tank, while others can be converted using specific kits.

You will likely appreciate having a fuel gauge to monitor how much gasoline remains in your portable generator during a blackout.

If the oil level drops below the minimum requirement, the generator will shut down to prevent engine damage. While this is standard for stationary units, it is becoming increasingly common on portable models.

Four or more outlets on a portable generator allow you to distribute the power load more effectively, though we suggest using them for only a few devices at home or while at a campsite. See the following section regarding transfer switches.

A removable console connects to the generator, allowing you to plug in appliances without running potentially hazardous extension cords outdoors.

A transfer switch is far more convenient than an extension cord and allows you to safely connect a portable or home standby generator to your circuit panel using a single cable. This eliminates the need to worry about overloading extension cords, which can cause overheating and fires.

Using a transfer switch also allows you to power essentials that lack a plug, such as water heaters, well pumps, and overhead lighting.

Here are a few essential notes regarding transfer switches:

We recommend having a licensed electrician install your transfer switch. According to Angi, the average installation cost is approximately $1,450. The electrician can also demonstrate how to operate the switch.

With whole-house generators, the transfer switch activates and deactivates automatically when the power grid fails or returns. For portable models, you will need to manually flip switches when the power goes out and reset them when grid power is restored.

Most transfer switches are designed for a 220-volt input, meaning you will need a generator with at least 5,000 watts of power.

You must decide which circuits will be connected to the transfer switch. Use a digital circuit breaker finder to identify which appliances and outlets are controlled by each breaker in your panel. Label them clearly so an electrician can connect the circuits for your essential items.

If you are looking to reduce costs, you might consider having an electrician install an interlock device. If this is compatible with your electrical system and meets local building codes, you will pay between $50 and $150 for the kit, plus $400 to $800 for labor, which is significantly cheaper than a transfer switch. The kit allows your generator to power your home’s entire circuit breaker panel and prevents the generator from running once grid power is restored. This is crucial, as running a generator while the grid is active could damage your electronics and potentially electrocute a utility worker.

A transfer switch is safer and easier to use than an extension cord, allowing you to power entire home circuits with greater security.

To evaluate generator performance, our engineers load each model with various essentials you might use during an outage, such as a well pump, space heater, or window AC unit. We verify that the generator can handle its rated load and observe how it reacts to sudden voltage spikes, such as when a refrigerator compressor kicks on while the generator is already near capacity. The best models handle these spikes easily, while others may stall or trip a circuit. A high-output generator that struggles with power quality or delivery might fail when bogged down.

We also evaluate how easy a generator is to use and move, how efficiently it consumes fuel, and its total run time on a single tank.

To test for safety, we subject each generator to various scenarios designed to simulate common consumer misuse. Our custom-built test chamber is equipped with calibrated carbon monoxide sensors, and we record CO levels throughout the container while the generator is running, noting how quickly each unit shuts down when levels become hazardous.

Finally, to reduce the risk of carbon monoxide poisoning, many portable generators feature a built-in sensor that triggers an automatic shutoff if CO builds up to dangerous levels in an enclosed space. We only test portable generators that include this built-in sensor. Some generators also feature engines that emit less CO by design.

Test data shows that this safety feature is likely to save lives, and we only recommend portable generators that pass our expanded CO safety technology testing.

Briggs & Stratton manufactures portable, inverter, and home standby generators. In addition to producing items under its own brand, it manufactures gasoline engines used by other generator manufacturers.

Cat is a smaller manufacturer of gasoline-powered portable generators. It focuses primarily on the construction market, with units designed for job sites.

Champion is a smaller manufacturer of various generator types, ranging from portable units and small gas-powered inverters to large standby generators that can power an entire home using natural gas or propane.

DeWalt is best known as a tool brand, but it produces gas-powered portable and inverter generators aimed at contractors. Its products are sold primarily at Home Depot.

Echo is a smaller outdoor power equipment company that is relatively new to the generator market. Most of its models are mid-sized, and many feature low-carbon-monoxide engines.

Generac is one of the largest generator manufacturers in the U.S. It produces everything from portable units to home standby generators, and its products are widely available at Home Depot and through smaller dealers.

Honda has a reputation for manufacturing stellar generators, particularly inverter models. It sells its relatively expensive portable and inverter generators through small dealerships rather than home centers.

Ryobi is a tool brand exclusive to Home Depot. Its low-CO generator was the first of its kind on the market, and it offers both portable and inverter models.