Variable Income Budget Calculator
Enter your last few pays. See what a percentage split gives you on every one of them, and what a fixed bank auto transfer does to the same weeks.
Three to six of your actual pays. A good week, a quiet week, and a typical one.
Rename these to match your own accounts. The last bucket is treated as the everyday account the money lands in.
Rent, power, insurance, the things that do not move when your hours do.
Pay by pay: percentage split versus fixed auto transfer
The fixed auto transfer is set from your average pay, which is how most people set one up.
What the fixed transfer costs you across these pays
Your recommended baseline
Percentages only work if something applies them
PayDay sees the pay land, whatever the amount, and splits it by your percentages the same day. No fixed dollar figure to guess, nothing to redo when your roster changes.
Join the PayDay waitlistBudgeting when every pay is a different number
Most budgeting advice quietly assumes the same amount lands every fortnight. That is not the working life of a shift worker picking up whatever the roster gives, a casual worker on call, a contractor waiting on invoices, a tradie whose week depends on the weather, or a freelancer with three clients paying on three different cycles.
The scale of it is not small. Stats NZ recorded 130,000 underemployed people in the June 2025 quarter, meaning people working part time who want more hours, in its Labour market statistics release published on 6 August 2025. Underemployment is a decent proxy for hours that move around, and hours that move around mean pay that moves around.
Why the fixed transfer keeps losing
A bank automatic payment is a dollar amount and a date. It cannot read your balance and it cannot read your pay. Set it from your average and you have built a rule that is wrong on almost every pay you ever get. The calculator above shows both failure modes at once. On a quiet pay it reaches for more than arrived, so the everyday account is stripped bare or the payment dishonours. On a strong pay it takes the same average slice and leaves the surplus sitting in the account you spend from, which is exactly where surplus goes to die.
Notice that the over transfers and the amounts left behind cancel each other out over the period. That is the trap. The totals look fine at the end of the year while every individual week was wrong. We go through the mechanics in more detail in PayDay versus bank auto transfers.
What a percentage split does instead
A percentage is a rule about the pay, not a rule about the calendar. Forty percent of a quiet pay is smaller than forty percent of a big one, and both are affordable, because the rule scales with what actually arrived. You never have to log in and adjust anything when your hours change, and you never have to remember which week you are in.
The trade off is that a percentage of a quiet pay may not clear a bill that does not shrink. That is what the recommended baseline above is for. It works out the smallest bills percentage that still clears your fixed bills on your worst recent pay, so the rule holds on the week it matters. For the wider approach, read our guide on how to budget on a variable income in New Zealand.
If you are self employed
Contractors, sole traders and freelancers carry a bucket that employees do not: tax. Because it is charged on income rather than on a flat schedule, it is the bucket best suited to a percentage. Set it once and every invoice that lands is already accounted for. We compare the tools for this in the best money apps for freelancers in New Zealand.
How PayDay connects
PayDay connects to your bank through Akahu, New Zealand's open finance platform. You approve the connection with your bank and you can revoke it whenever you like. If you want the splits on this page to run by themselves, join the waitlist.
Frequently asked questions
Why does a bank automatic payment not work when my pay changes?
A bank automatic payment moves a fixed dollar amount on a fixed date. It has no idea what landed in your account. On a quiet week the transfer still tries to take the full amount, so it either fails, dishonours, or leaves you short for the rest of the week. On a big week it takes the same amount it always takes, so the extra just sits in your everyday account and gets spent. A percentage split scales with whatever actually arrives, so both weeks are handled by the same rule.
How many pays should I enter?
Three to six recent pays is enough to see the shape of your income. Try to include one good week, one quiet week and one that feels normal. If you enter only your best weeks, the calculator will flatter you and your bills will still get missed in July.
What percentage should I put aside for tax if I am self employed?
That depends on your income and your expenses, so treat any single number as a starting point rather than advice. Contractors and sole traders commonly set aside somewhere in the 20 to 33 percent range against income tax, ACC levies and GST if they are registered. Check your own position with Inland Revenue or your accountant, then put that figure into the tax bucket above.
What if my worst week cannot cover my fixed bills at all?
The calculator will tell you when the percentage needed for bills goes above 100 percent of your lowest pay. That is a real signal, not a maths error. It usually means you need a buffer built from good weeks, a lower fixed cost base, or a smoothing account that holds one pay cycle in reserve so a quiet week draws on the last good one.
Does PayDay have access to my bank?
PayDay connects to your bank through Akahu, New Zealand's open finance platform. You approve the connection with your bank, and you can revoke it at any time.