Calculate the share of spending on water
A tenant wants to know whether water accounts for a larger share of combined utility spending after a summer increase. They record simulated bills for both utilities.
Open TrackerInputs and calculation
| Month | Utility | Usage | Bill | Budget | Variance | Month change |
|---|---|---|---|---|---|---|
| 2025-06 | electricity | 360 kWh | 90 | 100 | -10 | — |
| 2025-06 | water | 10 m³ | 30 | 45 | -15 | — |
| 2025-07 | electricity | 360 kWh | 90 | 100 | -10 | 0 (0%) |
| 2025-07 | water | 20 m³ | 60 | 45 | 15 | 30 (100%) |
June water share = 30 ÷ (90 + 30) = 25%. July water share = 60 ÷ (90 + 60) = 40%.
What the comparison shows
The share rises 15 percentage points even though electricity spending is unchanged. Adding kWh and m³ would have no useful meaning.
Assumptions and limits
The tracker shows per-utility amounts and trends. Calculate the share separately, using currency amounts for the same month.