Which power station calculator do you need?

Which calculator answers your question?

Which calculator should you open first?

Open the runtime calculator first if your question is how long a station lasts, and the solar recharge calculator if your question is how fast you can refill it. If your plan includes recharging from panels, you need both, in that order.

• Power station runtime calculator. Answers "how many hours will this run?" and "can this station start my fridge?" It covers 56 models from 6 brands and 49 appliances, and it checks both running and start-up watts.
• Solar recharge calculator. Answers "how many hours of sun to get back to full?" It works with the 51 models whose makers publish a maximum solar input.

The runtime tool tells you how much energy you spend. The solar tool tells you how much you can put back. Comparing the two is how you find out whether a setup can keep going day after day or only covers a fixed stretch.

What should you gather before you start?

Collect the watts of each appliance, how many hours a day each one runs, and, for solar, your panel ratings and a rough idea of your local sun. Ten minutes with labels and a notepad gives you your own figures in place of the typical ones built into the tools.

• Appliance labels. Look for input watts, or volts and amps you can multiply. Advertised output can be lower than what the appliance pulls from the outlet; a microwave's cooking power is the classic case. (Features and Specifications - Microwave Oven - NN-SU696SAWH, Panasonic North America, 2026)
• Hours of use. Write down how long each load really runs in a day, and which loads run at the same time. A list of things that overlap matters for the inverter check; total hours matter for the battery.
• Start-up behavior. Note anything with a motor or compressor: fridges, freezers, pumps, air conditioners and power tools. Those are the loads that test the surge rating.
• Panel ratings. Add up the rated watts of the panels you own or plan to buy.
• Your sun. Peak sun hours depend on where you are, the season and the weather. Winter in a northern state gives far fewer than summer in the Southwest. Snow and short days cut output further. (Loss Factor Assessment in the 8GW PV Fleet Performance Data Initiative (DuraMAT virtual seminar slides, Deline & Muller), National Renewable Energy Laboratory, U.S. DOE, 2022)

How do you plan an off-grid weekend with both tools?

Size the battery for one day of use in the runtime calculator, then check in the solar calculator whether your panels can refill that day's energy in the sun you expect. If they can't, you either carry a bigger battery for the whole trip or cut your loads.

1. List one day of loads. Add every appliance you will use in a typical day to the runtime calculator, with your own watts and quantities.
2. Find a station that lasts the day. Switch between models until the runtime comfortably covers 24 hours, or the hours you are awake if nothing runs overnight. Make sure neither chip turns red.
3. Note the average draw. The runtime result shows it. Multiply it by the hours you need to get the day's energy in Wh.
4. Check the refill. Pick the same station in the solar calculator, enter your panel watts and the peak sun hours you expect. If it shows a day or less to get back to full from empty, the panels can keep up with a full day's use.
5. Plan for the bad day. Re-run the solar step with fewer sun hours. If a cloudy day leaves you short, decide in advance what you will switch off.

For a two-night trip with no sun at all, skip the solar step and look for a station whose runtime covers the whole weekend. With no recharge, the battery has to hold the whole weekend's energy on its own, so compare the extra weight against carrying panels. The best power stations for camping list is a good place to start that comparison.

How do you plan outage backup with the calculators?

Start with the loads that protect health, food and communication, find how long a station runs them together, and then decide whether solar is worth adding for a longer outage. Outages that run past a day are common enough to plan for. (2020 RECS Table HC2.1 Structural and geographic characteristics of U.S. homes, by housing unit type, 2020, U.S. Energy Information Administration, 2023)

A closed fridge stays cold for hours without power and a full freezer for much longer, so you don't have to run them nonstop. (Power Outages, FEMA / Ready.gov, 2026) That lets you cycle them on and off and stretch a smaller battery. Enter the fridge, router, phone charging and a few lights in the runtime calculator. If someone in your home relies on a medical device, check its draw with the device maker before you trust any estimate.

If the result falls short of the outage length you want to cover, you have three levers: a bigger station, fewer loads, or panels to recharge during the day. The solar calculator shows how much the third lever helps in your season. For hardwiring a station to your home's circuits, read the guide to transfer switches and use a licensed electrician. The best power stations for home backup list narrows the field once you know your numbers.

How should you read the results?

Treat every result as an upper bound for good conditions and plan to use less than it shows. Both tools assume a full battery and rated specs, and any loss outside those specs isn't in the math.

• Runtime. Most loads count as running nonstop, which helps you. Battery age, cold weather and the station's own idle draw work against you. Leave a clear margin.
• Solar. A panel's rating comes from lab conditions, and outdoors heat, angle, dirt and passing clouds each take a share, which is why the solar tool lets you lower the output percentage.
• Red chips. A red start-up or charging chip is a hard limit. It won't go away with a bigger battery or more panels.

When should you use the appliance pages or best-for lists instead?

Use an appliance page when you care about one device, and a best-for list when you want a shortlist of models for a job. The calculators are most useful for mixes of loads and for your own numbers.

The can-it-run pages answer one question per appliance across every model at once, such as which stations start a refrigerator. That is faster than switching models one by one in the calculator. Best-for lists already apply the sizing for common jobs. Go back to the calculators when your setup is unusual or you want to check a specific mix.

What can't any power station calculator tell you?

No calculator can tell you how a specific unit behaves in your conditions. It can't see your battery's health, the temperature where you store and use it, or how much your appliances really draw when they cycle. A plug-in energy meter on your own appliances is the best fix for the last one.

Calculators also can't judge things that aren't in the spec sheet, such as noise, weight you are willing to carry or how a station handles a power cut. Use them to rule models in or out, then read each model page for the rest.

Where do the calculators' numbers come from?

Every station spec comes from the manufacturer's official US spec page or manual, and every runtime is calculated, not measured. The runtime tool applies 85% inverter efficiency to rated capacity. Appliance watts are typical figures from published sources, and you should replace them with your own. The full method, sources and assumptions are on how we research.