For a typical full-size refrigerator, plan on about 1,500Wh of usable power per day: a fridge that draws 150W while its compressor runs, running the equivalent of about 10 hours a day, uses 150W x 10 hours = 1,500Wh. Because a station delivers about 85 percent of its rated capacity after conversion losses, that day of refrigeration takes a rated capacity of about 1,765Wh. In the seven-station catalog we link to, that means the 2,048Wh class is the size that covers a full-size fridge for a full day per charge. Smaller stations still have a job: a 1,024Wh station covers an efficient fridge overnight or a mini fridge for a full day, and every figure here is a planning estimate you can adjust to your own fridge.
This calculator is preloaded with that typical full-size fridge: 150W, 10 hours a day, quantity 1, one day per charge. The 10 hours is compressor run-time equivalent, not 24 hours of continuous draw: a fridge compressor cycles on and off all day, and 10 hours is the middle of the typical 8-to-12-hour daily run-time range for a full-size fridge in a normal kitchen. It is not a claim that your fridge runs exactly 10 hours; it is the planning number that turns a cycling appliance into honest math. Change the watts to match the label inside your fridge door, change the hours if your fridge is older or lives in a hot garage, add a freezer, lights, or a router as extra rows, and the calculator totals everything, shows the math, and matches you to the smallest station we link to that covers it. For a mixed whole-home load, the general Power Station Size Calculator does the same job with a wider preset list, and our sizing guide explains the formula behind both.
Every figure on this page is a planning estimate built from manufacturer specifications and typical published draw ranges, not a measured result, a hands-on test, or a rating. Real draws vary with the fridge model, its age, the room temperature, and how often the door opens. Our refrigerator runtime guide works through the same math as runtime tables, including how long each common station size lasts against 100W, 150W, and 200W fridges.
How fridge duty cycle works
A refrigerator does not draw power continuously. Its compressor runs until the interior reaches the set temperature, then switches off while the insulation holds the cold, then runs again. That on-off pattern is the duty cycle. A typical full-size fridge in a 70-degree kitchen runs its compressor about 35 to 50 percent of the time, which works out to roughly 8 to 12 hours of actual compressor run-time spread across 24 hours of wall-clock time. That is why this calculator asks for hours of run-time equivalent: enter 10 hours for a typical full-size fridge and the math prices a full day of refrigeration, even though the fridge is plugged in for 24.
Entering 24 hours at full running watts is the most common sizing mistake with fridges: it prices the compressor as if it never rests and overstates a day of use by about two and a half times (150W x 24 hours = 3,600Wh instead of about 1,500Wh). The opposite mistake is just as real: a fridge in a hot garage, an older unit with worn seals, or a household opening the door all day can push run-time toward 14 hours or more. If your fridge is older than about 15 years, or the room is hot, set the hours to 12 and the watts toward the top of its range and let the calculator show you the larger answer honestly.
There is a second way to sanity-check the daily number. Many fridges carry an energy label with estimated yearly electricity use. Divide that yearly figure by 365 to get watt-hours per day: a fridge rated at 550 kWh per year uses about 1,507Wh per day, almost exactly the preloaded estimate on this page. If your label says 700 kWh per year, plan on about 1,918Wh per day and expect the calculator to point you at daily recharging or the largest station class. A plug-in watt meter left on the fridge for a full day gives the most exact figure of all, because it measures the cycling directly.
Running watts vs starting watts: the surge warning
The watts in this calculator are running watts: what the compressor draws while it is running. When the compressor first kicks on, it draws a short startup surge of about 3 to 5 times its running watts for a few seconds. A 150W fridge can spike to roughly 600 to 800W at startup, and an older or larger unit can surge past 1,000W. The station has to clear that spike with its continuous output rating, or the inverter trips and the compressor never starts, however much capacity the battery holds.
Be clear about what the calculator checks: it compares station output against your total running watts, not against the startup surge, because surge depends on the individual compressor. Make the surge check yourself before you buy. As planning guidelines, a mini fridge wants 300W or more of continuous output, a modern full-size fridge wants 800 to 1,000W or more, and an older or large fridge wants 1,200W or more. Against the seven stations we link to, that makes the EcoFlow River 2 Pro (800W output) a borderline start for a full-size fridge even where its capacity fits a smaller load, and the 1,500W to 3,200W stations (Jackery Explorer 1000 v2, EcoFlow Delta 2, BLUETTI Elite 100 V2, Anker Solix C1000, EcoFlow Delta 2 Max, BLUETTI Apex 200) comfortable for typical residential fridge surges. The exact surge figure for your fridge is the locked-rotor amps (LRA) on the compressor label, multiplied by 120 volts. This warning is also covered in our refrigerator runtime guide.
Common planning ranges
Use these ranges when you edit the preloaded row. Running watts come from the label inside the fridge door or the manufacturer spec sheet; if the label lists only amps, multiply amps by 120 to get the rated watts, and expect real running draw at or below that figure. Daily watt-hours below use the same 10-hour run-time equivalent as the calculator.
- Mini fridge or dorm fridge: 50 to 100W running. At 10 hours of run-time equivalent, about 500 to 1,000Wh per day. A 768Wh to 1,024Wh station covers a mini fridge for a day in most cases.
- Full-size top-freezer fridge: 100 to 200W running. About 1,000 to 2,000Wh per day. The preloaded 150W row sits in the middle of this range, which is where most full-size fridges plan out.
- Full-size French-door or side-by-side fridge: 150 to 250W running. About 1,500 to 2,500Wh per day. At the top of this range, no single station we link to covers a full day, and daily recharging or solar becomes part of the plan.
- Chest freezer: 100 to 150W running. About 1,000 to 1,500Wh per day, though a full, unopened freezer cycles less than these figures assume and holds its temperature for many hours with no power at all.
- Older fridge, pre-2010: 200 to 300W running. About 2,000 to 3,000Wh per day. Age is expensive here: an old fridge can use twice the energy of a modern efficient model of the same size.
Worked examples
- The preloaded full-size fridge: 1,500Wh per day. 150W x 10 hours = 1,500Wh, a rated capacity need of about 1,765Wh. The EcoFlow Delta 2 Max (2,048Wh, about 1,741Wh usable) is the smallest station we link to that covers a full day per charge, with roughly 16 percent to spare. Every 1,024Wh-class station falls short of a full day at this draw, however good its output rating is.
- A mini fridge for a full day: 750Wh. Change the row to 75W x 10 hours and the need drops to 750Wh, a rated capacity of about 882Wh. The EcoFlow Delta 2 is the smallest station we link to that covers it, and the BLUETTI Elite 100 V2 is shown with more headroom. The 768Wh River 2 Pro falls just short on usable capacity at about 653Wh.
- Overnight coverage only: 750Wh. If the goal is keeping a 150W fridge cold through the night rather than a full day, about 5 hours of run-time equivalent (150W x 5 hours = 750Wh) is the planning figure for the overnight stretch, and the same 1,024Wh class covers it. Size for the stretch you actually need to bridge, not automatically for 24 hours.
- Two days without recharging: 3,000Wh. Set Days per charge to 2 on the preloaded fridge and the need doubles to 3,000Wh. No single station we link to covers it: the calculator honestly shows the Delta 2 Max as the biggest we link to and what it actually covers, instead of pretending a smaller station stretches. The practical fixes are a recharge partway through, solar input during the day, or a second unit.
- Fridge and chest freezer together: 2,700Wh per day. Add a chest freezer row at 120W x 10 hours (1,200Wh) to the preloaded fridge (1,500Wh) and the combined day is 2,700Wh, past every single station in the catalog. One workable plan from our runtime guide: power the fridge, which warms in about 4 hours unopened, and let a full, unopened chest freezer coast, which can hold safe temperatures far longer.
The seven stations this calculator can recommend
Recommendations come only from the same seven stations as our main Power Station Size Calculator, with manufacturer specifications, pictured cards, and current check-price links: EcoFlow River 2 Pro (768Wh, 800W output, about 18.2 lbs), EcoFlow Delta 2 (1,024Wh, 1,800W, about 27 lbs), BLUETTI Elite 100 V2 (1,024Wh, 1,800W, about 25.3 lbs), Anker Solix C1000 (1,056Wh, 1,800W, about 28.4 lbs), Jackery Explorer 1000 v2 (1,070Wh, 1,500W, about 23.8 lbs), EcoFlow Delta 2 Max (2,048Wh, 2,400W, about 50 lbs), and BLUETTI Apex 200 (2,560Wh, 3,200W output, about 59.3 lbs). If none of them covers your watts, hours, and days, the calculator says so and shows the biggest station we link to and what it actually covers, instead of stretching a smaller station into a fit. One honest pattern to expect: because a full day of full-size refrigeration is about 1,500Wh, the Delta 2 Max is the only full-day answer in this catalog for a typical fridge, and the smaller stations earn their place on mini fridges, efficient models, and overnight coverage.
Mistakes to avoid
- Entering 24 hours at full running watts. That prices the compressor as if it never cycles off and roughly doubles or triples the station you think you need. Use run-time equivalent hours: about 10 for a typical full-size fridge.
- Checking capacity and forgetting the surge. A station can hold enough watt-hours and still fail to start the compressor. Confirm its continuous output clears your fridge startup surge, not just its running watts.
- Treating the label amps as the continuous draw. Amps x 120 gives the rated maximum, not the average draw. Sizing everything off the maximum oversizes the station; ignoring it entirely undersizes the surge check. Use running watts for energy and the label for the surge ceiling.
- Forgetting the 85 percent factor. A 1,024Wh station delivers about 870Wh to your fridge after conversion losses. The calculator applies this for you, but it is why a station that looks big enough on its box can fall short in practice.
- Sizing for the fridge, then adding the freezer. A chest freezer adds roughly 1,000 to 1,500Wh per day of its own. Add every appliance you truly plan to run as its own row before you decide.
- Leaving no headroom. A hot day, a door left ajar, or a fridge working harder after a warm load of groceries all raise run-time. A recommendation with some spare capacity survives a bad day; one that fits to the last watt-hour on paper may not.
Questions and answers
What size power station do I need to run a full-size refrigerator? For a full day per charge, plan on about 1,500Wh of usable power for a typical 150W fridge, which takes a rated capacity of about 1,765Wh or more. In the catalog we link to, that is the 2,048Wh EcoFlow Delta 2 Max. For overnight coverage, a smaller efficient fridge, or a mini fridge, the 1,024Wh class is often enough; the calculator above shows which case your own numbers land in.
How long will a 1,000Wh-class station run my fridge? A 1,024Wh station delivers about 870Wh of usable power. Against a 150W fridge that is about 5.8 hours of compressor run-time, which the duty cycle spreads across roughly 9 to 12 hours of wall-clock time in a normal kitchen. Against a 100W fridge it is about 8.7 hours of run-time. Our runtime guide tabulates the same math for 500Wh, 1,000Wh, 1,500Wh, and 2,000Wh stations.
Why does the calculator use 10 hours instead of 24? Because the compressor cycles. Ten hours is run-time equivalent: the total time the compressor is actually drawing power across a day, in the middle of the typical 8-to-12-hour range for a full-size fridge. The fridge stays cold for all 24 hours; it only draws its running watts for about 10 of them. Entering 24 hours would price a fridge that never rests, which no real fridge does.
Can a 768Wh station run a full-size fridge? Briefly. The EcoFlow River 2 Pro delivers about 653Wh usable, or about 4.3 hours of run-time against a 150W fridge, and its 800W output is borderline against a typical full-size startup surge. It is a reasonable mini-fridge or short-bridge station, and the wrong tool for a full day of full-size refrigeration.
Can I run my fridge and freezer on one station? Add both as rows and let the calculator total them. A typical pair (150W fridge and 120W freezer, each at 10 hours) needs about 2,700Wh per day, which no single station we link to covers. Power the fridge first: an unopened fridge warms in about 4 hours, while a full unopened chest freezer holds far longer, so in a short outage the freezer often needs no power at all.
Why does the calculator sometimes say no station fits? Because at a full day or more per charge, a full-size fridge can pass the usable capacity of the largest station we link to, the 2,560Wh BLUETTI Apex 200. Rather than stretch a recommendation, the calculator shows that largest station and what it actually covers, so you can plan daily recharging, solar input, fewer days per charge, or a smaller load.
Sizing a mixed load, or the fridge plus a whole outage kit, rather than refrigeration alone? Run the full device list through the Power Station Size Calculator, then read the sizing guide for the formula, surge wattage, and tier-by-tier picks behind these numbers.
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Comparing models? See all 17 stations side by side in the Portable Power Station Comparison — specs, prices, and calculated fridge and CPAP runtimes.