How Long Does a Generator Last?

Want to know more about generators before you go shopping? Generators can be a matter of life or death, so knowing how long they’ll last is essential.

A typical portable generator can last 1500-3000 hours. However, some factors affect how much use you can expect from them. Home standby generators that cost tens of thousands will run for 10 to 20 years.

In this guide, you’ll learn more about things like:

  • How to calculate a generator’s runtime
  • How different generators last
  • How often you’ll need to replace generators

Using a wrong generator can damage or destroy it, so knowing what to expect before shopping is essential. Keep reading so you’re not caught off guard.

Old Cast Iron Diesel Generator
How Long Does a Generator Last? 7

How Long Does a Generac Generator Last?

Generac generators are typically long-lasting, and a good portable model can last up to 3000 hours of use. The example shown in the image above is over 50 years old, although they don’t make them like they used to.

Another reason for their shorter life, like many things, is efficiency. Due to a tighter and more effective output, modern generators are put under great demand.

Generator Run Time Calculator

The easiest way to calculate a generator’s run time is by using this equation: [Average Gallons Per Hour] x [Gallons Per Tank]. For example, if your generator uses one gallon per hour and has a six-gallon tank, you can expect six hours of performance.

How Long Will a Whole House Generator Run on Natural Gas?

Whole-house generators are significantly more durable than regular portable generators so you can get more active use. In theory, a whole-house natural gas generator can run almost indefinitely.

However, many manufacturers recommend limiting the runtime to about 500 continuous hours before stopping it from doing maintenance. This is slightly less than three weeks of running.

The 500-hour limit isn’t universal, however. Some manufacturers make generators for long-term use, which can last several years. With maintenance, they may last even longer.

Continual generators are too expensive for most household needs, especially if you don’t have enough natural gas to use through power outages. However, they’re a good option for people who want to live as far off the grid as possible while still having a lot of electricity.

How Long Do Portable Generators Last?

Portable generators last between 1000 and 3000 hours, depending on the model, how heavily you use them, how well you maintain them, and whether you store them properly.

What Is the Life Expectancy of a Portable Generator?

The life expectancy of a portable generator is how many hours of runtime you can expect from it under ideal conditions. Ideal conditions include performing maintenance exactly as the manufacturer recommends.

Models have different life expectancies, but most portable generators will last between 1000 and 3000 hours (about 41-123 days of running). Anything below this range is too low to be a decent generator, while anything higher indicates a particularly high-quality product.

Exhaust Pipe Of A Portable Gasoline Generator
How Long Does a Generator Last? 8

How Often Do You Need To Replace a Generator?

How often you need to replace a generator depends on how much you use it and how well you maintain it. Most generators are durable and don’t degrade very fast as long as you keep them in a dry area without many temperature changes.

Generators may need maintenance after a long storage period, but you can realistically expect them to last for 10 or 20 years under optimal conditions. If you use your generator heavily, you may need to replace it as often as every year.

Take a look at the different types of generators below. The cost reflects the power and the number of years you’ll be able to run them.

Generac Guardian 24Kw Home Standby Generator With...
31 Reviews
Generac Guardian 24kW Home Standby Generator with…
  • Save up to 8,000 dollars in product and installation costs (when compared to competitive output products)
  • Takes up 70% less space (when compared to competitive output products)
  • PWRview, Generac’s home energy management system, allows generator owners to monitor and manage home energy usage, leading to a reduction in electric utility bills of up to 20%
Bestseller No. 1
Duromax Xp4400E Gas Powered Portable...
6,228 Reviews
DuroMax XP4400E Gas Powered Portable…
  • Plenty of Power – With 4,400 starting watts and 3,500 running watts, this unit can handle heavy loads, from lights and a refrigerator to a home air conditioner and high amperage power tools
  • Powerful Engine – The DuroMax 210cc OHV engine is a workhorse that provides plenty of power to handle multiple jobs, from powering high voltage appliances to heavy duty power tools
  • MX2 Technology – Get the maximum power from each of the 120-volt receptacles. Choose between operating the generator at both 120V and 240V simultaneously, or at 120V only with full power. Ideal for usage with RVs
Bestseller No. 2
Westinghouse WGen3600v Portable Generator, 4650…
  • 3600 Running Watts and 4650 Peak Watts; Recoil Start; 4 Gallon Fuel Tank With Fuel Gauge; Up to 14 Hours of Run Time Per Tank
  • Features One 5–20R 120V Household Duplex Receptacle, One RV-Ready TT-30R 30 Amp Receptacle, and One L5-30R 30 Amp Receptacle; All Outlets Have Rubber Covers for Added Safety
  • Plug-and-Play: Comes With Oil, an Oil Funnel, a Tool Kit, and a User’s Manual to Get You Started Right Out of the Box (Minimal Assembly Required)
SaleBestseller No. 3
PowerSmart Portable Generator, 2200 Watts Inverter…
  • STRONG POWER FOR LONGER RUNTIME – This 2200W inverter generator equipped with 4 stroke OHV single cylinder engine and forced air cooling system that give you better supprt once in use. Spark plug gap 0.024-0.031 inch, displacement 79cc and fuel tank capacity 1.05 gallons oil capacity 16.9fl.oz. Rated wattage 1900W, surge wattage 2200W.
  • PORTABLE POWER STATION FOR OUTDOOR CAMPING & HOME USE – The portable inverter generator specially designed for charging laptops, mini-cooler, drone, other outdoor electronics and backup for few home essentials. It features with 2* AC outlet(120V), 2*USB-A ports(5V) and 1* DC car port(12V). Quarter load can run up to 10.5hrs, power your wherever you go.
  • SIMPLE TO USE AND CARRY EVERYWHERE – This generator is portable with ulta-lightweight 42.5 pounds. The dimension of the power generator is 20.9” length x 13.8” width x 19.9” height. More compact than you imagine. Parallel ready design enables this inverter to connect with 2 PowerSmart generator for double your output support up to 3800W. Great solution for your outdoor needs.