Money

How to budget for bills that change every month

Electric, water and phone bills move around. Pull twelve months, find the low and the high, and plan toward the high so the spike month is not a surprise.

1 min read26 September 2026

A fixed bill is easy to plan for. A bill that changes every month is not, and the usual response is to guess, then be surprised in the months the guess was low.

The fix is to stop treating a moving bill as a single number. It is a range, and it is much easier to plan around a range you have looked at than a figure you have imagined.

The method

  1. Pull twelve months

    Find the last twelve statements or bills for the one you are planning.

  2. Find the low and the high

    Note the smallest and the largest amount in that year.

  3. Plan toward the high

    Use the high, or something close to it, in your budget.

  4. Set the gap aside

    In the months the bill is low, keep the difference for the spike.

  5. Check again

    Once a season, look at whether the range has moved.

An example

An illustration only. Use your own twelve months.

  • Lowest month

    Amount
    $60
  • Highest month

    Amount
    $122
  • Midpoint

    Amount
    $91
  • Plan toward

    Amount
    $122
  • Set aside in a low month

    Amount
    $62

Bills that usually move

4 things to do

Ticks are for this visit only. Nothing here is saved anywhere.

The spike month

The month the bill is highest is the month it hurts. Setting the difference aside in the cheaper months is a small sinking fund for exactly that. There is a fuller version of the idea in sinking funds explained. For the wider list of what falls due, see how to make a monthly bills list.

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