Flat Power Calculator
I made a small calculator for the flat power bill, keeping the calculation and the message about what each person owes close to the same inputs.
Independent development. TypeScript calculation, formatting and Home Assistant integration.
The project started with the monthly power bill for the flat, and I kept the calculation separate from its formatting so the amount shown in the interface could also be used when communicating the split, with the browser interface taking the figures while the calculation module kept the sharing rule in one place.
The TypeScript modules separate the split calculation, display formatting and Home Assistant access, with a browser interface for entering the relevant figures and working through the result.
It stayed a small household tool, though that scale made the rule easier to inspect, as there was one bill and a particular sharing arrangement behind the numbers.
The catalogue date follows the first preserved commit on 21 April 2026.
Outcome
An implemented household calculation tool with a clear separation between inputs, split logic and output formatting. The cover shows the workflow using no personal bill amounts.