Solar Panel Sizer: Off Grid

Solar Panel Sizer works out how much solar you need — for an off-grid cabin, an RV, a backup system or a client's home.

START FROM WHAT YOU USE
• List your appliances from 60+ presets (fridge, well pump, lights, laptop…) or add your own with watts, hours and quantity.
• Or enter your power bill: one monthly kWh figure or all 12 months.
• See your daily energy use in kWh and your peak and surge load.

GET THE SYSTEM SIZE
• Panel count for the panel you pick, and total array watts.
• Battery bank size in kWh and amp-hours, from your days of autonomy, depth of discharge and system voltage (lithium or lead-acid).
• Inverter size with surge check, and charge controller amps.
• Off-grid, hybrid or grid-tied systems.

REAL SUN DATA FOR YOUR SITE
• Monthly sun hours from NASA POWER, for panels tilted at your latitude.
• Search 2,000+ cities offline, use your current location, or enter sun hours yourself.
• Size for the worst month or the yearly average, and see which months fall short.

SHOW YOUR WORK
• A monthly chart of energy made against energy used.
• Every formula with your own numbers, so you can check each step.

FOR INSTALLERS (PRO)
• Client quote PDF with your logo, business details, line items, tax and totals.
• Save unlimited projects, track each job as draft, quote sent, won or lost, and duplicate a job to start the next one.
• Keep your own equipment list and prices.

Works in imperial or metric units, in 16 languages, with or without an account. Sign in with Google to back up your projects.

SUBSCRIPTION
Solar Panel Sizer is free to use for sizing and one saved project. Solar Panel Sizer Pro unlocks the quote PDF and unlimited projects. Choose a weekly plan, a yearly plan with a 3-day free trial for new subscribers, or a one-time lifetime unlock. Payment is charged to your Google Play account. Subscriptions renew automatically unless you cancel before the end of the current period. Manage or cancel any time in Google Play > Payments & subscriptions. Lifetime is a single payment and never renews.

Estimates only. Verify with local code and a licensed professional.

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