How much to save each pay for a bill
Registration, insurance, rates, school fees — the ones that arrive as a whole number rather than a little each month. Put one in with how often you’re paid, and you’ll get the amount that actually covers it on the day, not the yearly average that leaves you short. No account needed.
Why the average is wrong
Most budgeting tools convert every bill to a weekly figure and add them up. It is a tidy number and it is honest about the long run. The trouble is that it describes a year you have already saved through, not the one you are standing in.
Registration due in four weeks does not care that its annual cost is $17 a week. It wants $900 on the day. Anything that spreads it evenly is quietly assuming you started saving eleven months ago, and if you did not, the gap never closes.
Common questions
- How much should I put aside each pay for a bill?
- Take what the bill costs, subtract anything already set aside, and divide by the number of paydays before it is due. A $900 registration due in four pays needs $225 a pay. Dividing by a whole year instead gives $17 a pay, which is the right answer to a different question.
- Why not just divide the bill by twelve?
- That works when the bill is a year away. It fails when it is closer, because it quietly assumes you have already been saving for the months that have passed. If you have not, the average never catches up and you are short on the day.
- What is a sinking fund?
- Money put aside a bit at a time for a known, irregular expense: registration, insurance, rates, school fees. The point is that the bill stops being a surprise, because the money was already there before it arrived.
- Does this work with fortnightly pay?
- Yes, and it matters. Fortnightly pay and monthly bills drift against each other through the year, so a month with three pays and a month with two need different treatment. The calculator counts your actual paydays before the due date.
One bill is arithmetic you can do here for free. A whole household is a different problem — a dozen bills, two incomes, and pots that have to stay solvent all year.