Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
Home Battery Sizing Calculator
Size a home battery storage system to cover a specific backup load for a chosen number of days without grid or solar input, accounting for depth of discharge, round-trip efficiency, and a safety reserve.
Battery capacity needed
29.63 kWh
20-40 kWh needs two stacked units. At ~29 kWh you are sizing for about 2 days of autonomy on a 10 kWh/day load; trimming autonomy by a day cuts capacity nearly in half.
This is the rated battery capacity needed to cover your backup load after depth-of-discharge, efficiency, and reserve losses; a single Tesla Powerwall is about 13.5 kWh usable.
Off-Grid Solar System Calculator
Size your off-grid solar system by calculating required solar panels, battery bank, and inverter capacity. Essential for cabins, RVs, or remote installations without grid access.
Key differences
| Home Battery Sizing Calculator | Off-Grid Solar System Calculator | |
|---|---|---|
| Category | Solar Energy | Solar Energy |
| Inputs required | 5 | 5 |
| Result | Battery capacity needed (kWh) | Total System Capacity (W) |
| What it does | Size a home battery storage system to cover a specific backup load for a chosen number of days without grid or solar input, accounting for depth of discharge, round-trip efficiency, and a safety reserve. | Size your off-grid solar system by calculating required solar panels, battery bank, and inverter capacity. Essential for cabins, RVs, or remote installations without grid access. |