About Power Station Tools
Power Station Tools is a small web tool built to answer one practical question, quickly and without a sales pitch: how long will a power station actually run my stuff — or how big a battery do I actually need to buy?
What Power Station Tools is
Power Station Tools is a set of free, browser-based calculators focused on portable power station runtime and sizing. You enter a battery capacity (or the hours you want covered) and the devices you plan to run, and the calculator converts that into a practical runtime or capacity estimate. It's built around real situations people actually plan for: a power outage at home, a weekend of camping, RV and van life, keeping a refrigerator or CPAP machine running, or a TV, gaming PC, or PS5/Xbox setup off-grid. This is a tool, not a company — there's no team, storefront, or product line behind it, just a project aimed at making that specific piece of math easier.
Why we built it
Power station spec sheets are genuinely confusing. A listing might quote capacity in Wh, output in W, and a surge rating in yet another number, and it's easy to mix those up — Wh and W measure different things, and neither one alone tells you how long a device will actually run. On top of that, real-world runtime depends on the power station's conversion efficiency and on how the load actually behaves, not just the numbers printed on the box. We built this site because doing that math by hand, or guessing, isn't a great way to decide whether a battery can handle what you need before you buy one or head out the door with it.
How the calculations work
Every result on this site comes from the same two formulas: Usable Energy (Wh) = Power Station Capacity (Wh) × Efficiency and Runtime (hours) = Usable Energy (Wh) ÷ Load (W). The calculator currently uses 85% as its default efficiency for these estimates — a reasonable planning figure, not a claim that every power station converts energy at exactly that rate. Efficiency varies by inverter design, age and load, which is why the calculator lets you adjust it yourself when you have a better number for your own unit.
Why results are estimates, not guarantees
Every figure this site produces is an estimate, and real-world consumption can differ for reasons the formula alone can't capture: inverter efficiency losses, how a specific load actually behaves under real conditions, compressor cycling in appliances like refrigerators, ambient temperature, general usage patterns, other devices drawing from the same battery at the same time, and differences between individual product models. A refrigerator or mini fridge is a good example — its compressor cycles on and off rather than drawing its rated wattage the entire time it's plugged in, so its real average consumption is meaningfully lower than its peak or nameplate figure.
How to read the device wattage values
The wattage figures built into each calculator are planning values used by this project for its own estimates — not universal specifications that apply to every model of that device. They're a reasonable starting point when you don't have a better number. If you know your own device's actual consumption — from its label, its manual, or a measurement — use that instead; it will always give you a more accurate result than a general planning figure. Measuring your own device's real draw over a long enough period (long enough to capture a full on/off cycle, for something like a fridge) with a plug-in power meter is generally the most reliable way to get a number specific to your situation. This site doesn't run a formal testing or review program on physical devices — the figures are orientative, not lab-measured specifications.
Independent of any manufacturer
Power Station Tools is not a power station manufacturer, retailer, or representative of any specific brand, and it doesn't currently have any sponsorship, affiliate, or commercial relationship with one. The figures and explanations on this site aren't influenced by any particular product line, and nothing here should be read as an endorsement of one manufacturer over another.
Limitations and safety
These calculators are informational tools meant to help you plan — they are not a substitute for your equipment's official manufacturer specifications. Before relying on a power station for anything that matters, check its rated continuous output, its peak/surge output, that its output is compatible with what you're plugging in, and its actual capacity, against the manufacturer's own documentation and instructions.
For anything where an interruption could have real consequences — a CPAP machine or other medical equipment, medication that needs to stay within a temperature range, food safety, or similar critical uses — check the specific guidance that applies to that situation (your equipment provider, a pharmacist, or the relevant safety information) rather than relying solely on an estimate from this site.
Privacy, in short
The calculators run entirely in your browser — the numbers you enter aren't collected or transmitted anywhere. See the Privacy Policy for the full details, including how analytics works and only loads after you consent.
Explore the calculators
- Runtime Calculator — how long a power station will run your devices.
- Size Calculator — what capacity you need for a given runtime.
- Power Station for a Blackout — planning for a home power outage.
- Power Station for Camping — a full off-grid trip setup.
- Power Station for RV — RV and van life power planning.
Get in touch
Feedback, corrections, or questions are welcome at hello@powerstationtools.com.