"How long will it run my stuff?" is the only power station question that matters, and spec sheets answer it badly — capacity in watt-hours means nothing until it meets your actual loads. So here's the answer as a tool: check your devices below, set their daily hours, pick a station class, and watch the runtime compute live. Then read on for what the numbers mean, where they bend, and how to make any result bigger for free.
Power Station Runtime Calculator
How the calculator thinks
The math is the same recipe our watt-hours guide teaches by hand: each device's typical draw times its daily hours sums to a daily watt-hour budget; the station's rated capacity gets an 85% haircut for inverter losses and real-world delivery; and runtime is simply the usable tank divided by the burn rate. Two honest caveats live inside every result. First, the device draws are typical classes, not your specific hardware — a watt meter weekend replaces our estimates with your truths, and it's the single best upgrade to any answer here. Second, the "combined running draw" line matters separately from runtime: it's the watts side of the two-number system, and if your simultaneous loads approach a station class's output rating, sequencing (fridge or microwave, not both) becomes part of the plan. The calculator deliberately shows both numbers because buying on capacity alone is the category's classic mistake.
Reading your result: the three verdicts
Results cluster into three stories. "Days" — your essentials fit comfortably in the class you picked; the remaining question is refill, and the calculator's solar note sketches whether a panel setup makes the runtime effectively indefinite (the drain-by-night, refill-by-day loop our refrigerator explainer builds around). "Hours" — the class covers an evening or a night; fine for weekend duty, thin for outages — either step up a class, add the expansion pack path from our expansion guide, or trim the load list to true essentials and recompute. "Minutes" — you checked a resistance-heat load, almost certainly the space heater, and the calculator is delivering this site's most repeated sermon: heat-making appliances devour batteries by design, and recognizing that on screen instead of during an outage is exactly why that row exists. Uncheck it, watch the runtime multiply, and plan heat by other means.
Making any number bigger for free
Before buying a class up, spend the free capacity. Run DC-capable devices on DC — CPAPs with manufacturer cables, USB-C laptops, 12V gear — and skip the inverter's tax entirely, the trick our medical guide quantifies. Sequence the burst appliances instead of stacking them. Feed the refrigerator's thermal mass (frozen jugs, closed doors) and its cycling average drops. Charge opportunistically from every source — the car on errands, the wall before the storm, the panel all day — so the tank starts full. And let the calculator's daily-budget line drive one honest edit pass of the load list: outage plans shrink dramatically when "everything" becomes "everything that matters," and the difference is usually a full station class of money.
The measurement upgrade
Our device rows are honest averages of wide classes — your refrigerator's vintage, your laptop's habits, and your CPAP's settings all move the true numbers, sometimes dramatically. The fix costs less than lunch: a plug-through watt meter on each load for a representative day converts every row above from estimate to fact, and the measuring exercise reliably and usefully surprises in both directions (the TV that sips less than feared; the old fridge that gulps double the modern average). Log the readings on the outage card, plug them back into the calculator's hour fields as adjusted mental math, and the tool graduates from planning aid to household instrument.
Match the class to a platform
Once the calculator names your class, Bluetti's lineup covers it — compacts for the hours verdicts, 1–2kWh units for the days verdicts, and the expandable stacks when the daily budget says grow.
Check Bluetti's current pricing →From estimate to plan
The tool's real product is the conversation it starts: your daily budget number, in writing, is the input every other decision on this site consumes — panel sizing from the portable panel guide, platform choice from the brand comparison, the expansion-stack math of the home backup guide, and the site's full sizing calculator when the mission graduates from a station to a system. Bookmark this page for the next storm warning, replace our estimates with your watt-meter numbers as you collect them, and let the runtime you can see beat the anxiety you can't. The station in the closet was always just arithmetic wearing a handle — and now the arithmetic runs itself, updates as your household changes, and answers the 2 a.m. question before anyone has to do math in the dark.
Frequently Asked Questions
How accurate is this runtime calculator?
It's a planning estimate built on typical device draws and an 85% usable-capacity discount — honest for choosing a station class, not a lab measurement. Replacing the defaults with your own watt-meter readings makes it personal and precise.
Why does adding a space heater collapse the runtime?
Resistance heat is the hungriest load class in any home — by design, since making heat from electricity takes enormous energy. Batteries are the wrong tool for it, and the calculator includes the row precisely to demonstrate that before an outage does.
What does the 85% usable capacity mean?
Rated capacity minus real-world overhead: inverter conversion losses, battery delivery under sticker, and temperature effects. Planning at 85% is why the calculator's predictions survive contact with reality.
Can solar really make runtime indefinite?
When a panel setup's daily harvest covers the daily budget, yes — the battery cycles instead of counting down. The calculator's solar note flags which budgets a 200W or 400W setup can realistically sustain in decent sun.
My combined draw is high — does that matter if runtime looks fine?
Yes — runtime is the tank, combined draw is the tap, and a station must satisfy both. If simultaneous loads approach your class's output rating, sequence the burst appliances or size the class up; capacity can't fix an output shortfall.