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Splitting guide

How to split utilities: by usage or by equal share?

The EvenRound team · EditorialPublished Updated 1 min read

The gym-rat's hot showers shouldn't punish the person who works from home. But the math has to be tractable.

Utilities are where roommate fights start. Equal-splitting feels fair until one roommate showers for 40 minutes daily, leaves the heat on, and has 10 friends over each weekend. Usage-splitting feels fair until you realise you can't actually meter individual showers. The honest middle ground is a hybrid: equal for fixed costs (internet, standing charges), usage-proxy for variable ones (electric, gas, water). Here's how.

Steps

  1. 01
    Separate fixed from variable costs

    Internet is fixed. Council tax is fixed. Electricity has a fixed standing charge plus a per-kWh variable. Identify which line on each bill is which.

  2. 02
    Equal-split the fixed portion

    Internet: equal among everyone, even the person on holiday. Council tax: equal. These are 'we're all here' costs.

  3. 03
    Use a usage proxy for variable costs

    Time-at-home is the cleanest proxy. Use a shared calendar to track 'days at home' - if Anna was away 5 days that month, her variable share is (25/30) of average. Or: count rooms occupied. Or: count shower-users.

  4. 04
    Be generous about partial weeks

    If someone left town for 4 days, give them a full week off. Fighting about half-weeks isn't worth it. This is one of the few categories where 'roughly fair' beats 'exactly fair'.

  5. 05
    Decide once, automate it

    After 2 months you'll have a sense of typical usage. Pick a default ratio (e.g., 35/35/30) and use it as a 'shares' split for every utility expense. Adjust only when someone's pattern materially changes.

Worked example

Three roommates, €220 electric bill, one was away 10 days

Standing charge €40 split equally = €13.33 each. Variable €180 split by days at home: Anna 30/30, Ben 30/30, Cara 20/30. Anna 30/80 = €67.50. Ben 30/80 = €67.50. Cara 20/80 = €45. Total: Anna €80.83, Ben €80.83, Cara €58.33.

Use the 'shares' split mode for variable utilities and 'equal' for fixed. Document the ratio in the group description so a new bill doesn't reopen the conversation.

Create a recurring utilities expense

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