Utility Bill Split Calculator

Work out utility bill split instantly with clear inputs, formula shown and shareable results.

About Utility Bill Split Calculator

Splitting a utility bill by person-days is fairer than a flat division when someone was away. Each person's share is their days present divided by the total person-days in the period, so a housemate absent for a week pays proportionately less of the heating and hot water.

Formula

Person-day split

my share = bill x my days / total person-days across the household

Worked example

With the default values below, Utility Bill Split Calculator returns My share of $39.71. Change any input above and every figure here is recalculated in your browser.

Inputs used

Bill amount: 148
People in the household: 3 people
Days I was present: 22 days
Days in the billing period: 30 days

Results

My share: $39.71
Even share: $49.33
Adjustment for absence: -$9.63
Cost per person-day: $1.6444

Step by step

1Values used
2Person-day split
3My share= 39.71
4Even share= 49.33
5Adjustment for absence= -9.63
6Cost per person-day= 1.6444

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or fees or charges into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Does this work for standing charges?

Not really. Standing charges accrue whether anyone is home, so many households split those evenly and apportion only the usage element by person-days.

What about very different usage?

If one person works from home with the heating on all day, agree a weighting rather than relying on days present alone.