Why Home Assistant's energy cost doesn't match your electricity bill

Free calculator · runs in your browser · nothing is sent anywhere

Home Assistant's Energy dashboard multiplies your kWh by a price. Your real bill also has a standing charge (a fixed amount per day), often fixed monthly fees, per-kWh levies and VAT. That is why the dashboard never matches the bill. Type the numbers from your bill to see the gap.

kWh used in the bill period (from Home Assistant)
Days in the bill period
Price per kWh (as typed in Home Assistant, before VAT)
Standing charge per day
Fixed fees for the whole period (meter rent, service fee...)
Levies per kWh (network, green energy... added together)
VAT %
VAT also on the standing charge and fees?

Fix it inside Home Assistant

Free: Aurum Bill Match (free) adds the standing charge to the Energy dashboard with Home Assistant's own helpers and one template sensor - no custom integration, nothing loaded from the internet.

Everything on the bill: Aurum Bill Match Pro (EUR 7) adds standing charge + monthly/yearly fees and credits + up to 3 per-kWh levies + VAT (also on fees if your bill does that) into one cost entity, plus a bill-period forecast. Tested on Home Assistant 2026.9.4.

Estimates from the numbers you type in - this page cannot read your contract; check against your next bill. The calculator runs in your browser only: what you type is not sent anywhere. No cookies; page views are counted without cookies. Made with AI assistance. Not affiliated with Home Assistant or the Open Home Foundation.

Questions

Why doesn't Home Assistant's energy cost match my electricity bill?

The Energy dashboard multiplies your kWh by one price. Your bill also has a standing charge per day, often fixed monthly fees, per-kWh levies and VAT.

Are the numbers I type sent anywhere?

No. The calculator runs in your browser only - what you type is not sent anywhere. The site itself uses no cookies; it only counts page views.

Can I fix it inside Home Assistant?

Yes. The free Aurum Bill Match adds the standing charge with Home Assistant's own helpers and one template sensor (no custom integration). Aurum Bill Match Pro (EUR 7) adds fees, credits, up to 3 levies and VAT into one cost entity. Tested on Home Assistant 2026.9.4.

Is the result exact?

It is an estimate from the numbers you type in - the page cannot read your contract. Check it against your next bill.