Free tool
Battery capacity calculator
Estimate the right battery size for your home, see projected savings, and get product recommendations. No signup required.
24 kWh
1 days
6 kWh
Estimates only. Assumes 90% usable depth of discharge and a $0.18/kWh blended rate. For illustration, not a quote.
Recommended capacity
26.5 kWh
25%
Solar offset
$394
Est. savings/yr
876 kg
CO₂ cut/yr
Sized for 1 day of backup at 24 kWh/day
Top matches for your profile
GridCell Vault 310
Shop now20 kWh · $7,600
PowerNest Vault 300
Shop now20 kWh · $7,600
HybridFlow Core 250
Shop now17.5 kWh · $6,500
How it works
01
Set your usage
Slide to match your daily kWh from your utility bill or smart meter.
02
Choose backup days
Pick how many days you want the battery to cover during an outage.
03
Add solar output
Enter daily solar generation to estimate offset and savings.
Common questions
- How accurate is this?
- This is a sizing starting point. Final capacity depends on inverter limits, peak loads, and local codes.
- What depth of discharge is used?
- We assume 90% usable capacity, typical for modern LiFePO4 home batteries.
- Need more help?
- Use the Battery Finder for personalized picks or browse our buying guides.