Build Your Backup Load
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Planning estimate only — not a quote, not installation advice, and not tax advice. Confirm the final size with a licensed installer for your home, panel, and utility rules.
Pick your appliances. See your battery. Tap an appliance — or drag it — into My Home, set how many you have, and watch the watts, the kWh, the battery size, and the cost range update live. No sign-up to play: the builder sends nothing anywhere.
How it works
Pick appliances
Tap or drag the things you want backed up into My Home. Fridge, TV, lights, fans, iron — the stuff in a normal American home.
See your numbers
Running watts, startup peak, daily kWh, battery size, and installed-cost range update live as you build.
Get quotes (optional)
Happy with your load? Ask for free quotes and installers in your area get your exact load with it — no guessing on the phone.
Appliances — tap or drag to add
Typical running watts from U.S. Department of Energy appliance tables. Your own appliance may differ — check its label. Tap a card to add one, or drag it into My Home.
My Home — your backup load
Starts with the essentials. Add more, change quantities, or remove things. Drop appliances here.
Same hours used by the battery size calculator.
Your numbers — live
Add appliances to see your size.
Example units (13.5 kWh each): 0 · Installed-cost range: —
Cost range uses the research range of $12,000–$16,000 installed per 13.5 kWh example unit. It is a planning range, not a quote. Peak watts = all running watts + the biggest single startup extra — your inverter must cover the peak.
Get free quotes for this exact load (optional)
Fill this in only if you want installers in your area to contact you with quotes. The builder above stays free and sends nothing — this form is the only thing that sends data, and only when you submit it.
Your load summary, time on this page, and how many appliances you picked travel with your details, so installers can see this is a real, worked-out load — not a bare phone number. Your location is the ZIP and state you type above; we do not track your GPS. See Privacy and Affiliate Disclosure.
Watts used — the table
Every appliance in the builder, with the typical watts and hours it uses here. These are planning values from U.S. Department of Energy appliance tables (via the LG&E Watt Finders Guide, “Information from Energy.gov”) and manufacturer nameplates — your own appliance may use more or less. Starting watts are shown only where a motor or compressor starts up.
Sources: U.S. Department of Energy, “Estimating Appliance and Home Electronic Energy Use” (typical wattages); LG&E Watt Finders Guide; FirstEnergy, “Understanding Electricity Usage & Costs”. Installed-cost range: research reports dated 4 November 2026 ($12,000–$16,000 per 13.5 kWh unit installed).
Formula shown on the page
Daily kWh = Σ (watts × typical hours per day × quantity) ÷ 1,000
Energy needed (kWh) = Daily kWh × Outage hours ÷ 24
Example units needed = Energy needed ÷ 13.5 kWh, rounded UP to the next whole unit
Same maths as the battery size calculator: 13.5 kWh is the example unit size from the research, not a brand recommendation. Usable capacity, inverter limits, solar recharging during an outage, degradation, and panel / utility rules are not included — confirm with a licensed installer and the manufacturer spec sheet.
Disclaimer: This is a planning estimate only, not a quote, not a recommendation to buy a specific product, and not tax, legal, electrical, or installation advice. Get a site-specific quote from a licensed installer and check your utility's rules before buying. No data is sent anywhere by this builder until you submit the quote form above.
Live status: published at homebatterycalc.com, not linked to any affiliate programme, and containing no affiliate link, ID, or discount code.
Frequently asked questions
Do I have to give my details to use the builder?
No. The builder runs entirely in your browser and sends nothing. Only the optional quote form sends your details, and only if you fill it in and tick the consent box.
Where do the watts come from?
Typical running watts from the U.S. Department of Energy appliance tables and manufacturer nameplates. Your own appliance may differ — check the label on the back or bottom. Figures are planning estimates, not a quote.
What happens after I ask for quotes?
Your load summary (appliances, watts, kWh, battery size, and cost range) goes with your name, phone, email, and ZIP to licensed installers in your area, who may call or text you about a quote. You can opt out anytime by replying STOP.
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