Find the right battery size
for your home.

BatterySizer analyses your actual energy usage, compares tariffs, and tells you exactly what size home battery storage system will save you the most money — with a clear payback timeline.

✓ No sign-up required✓ Upload your own usage data✓ UK tariffs supported✓ Instant results

How it works

Three steps to your personalised battery recommendation

01

Upload your usage data

Import a CSV export from your smart meter or energy supplier — or enter your annual consumption manually.

02

Select your tariff

Choose your current energy tariff from our UK tariff library, or enter a custom rate. We factor in time-of-use pricing.

03

Get your recommendation

See the optimal battery size, projected annual savings, and a clear payback period — so you can buy with confidence.

Built for homeowners

No guesswork. No sales pitch. Just accurate numbers.

Real usage analysis

We simulate your battery against your actual half-hourly consumption data, not averages.

Payback calculator

See exactly how many years until your battery pays for itself, based on current energy prices.

Multiple battery options

Compare leading home battery systems side by side to find the best fit for your home.

Tariff aware

Supports Octopus Agile, Economy 7, and standard rates — including export tariffs for solar homes.

Solar compatible

Have solar panels? We factor in your generation profile to maximise self-sufficiency.

Instant & free

No account needed. Get your full recommendation in seconds, completely free.

Ready to size your battery?

Takes less than 2 minutes. Free, instant, and no sign-up required.

Start for free