Irregular Income Budget Calculator
Turn a variable paycheck into a monthly budget. Enter 3-6 months of income for a safe baseline, the surplus to bank, and how long a buffer takes.
Irregular Income Budget Calculator
Your recent months of income
Enter the take-home money you actually received each month, after tax and after anything you hold back for tax. Gross invoices will overstate every figure on this page. A blank row is skipped; a typed 0 counts as a real zero-income month.
Three months is the minimum for a meaningful baseline, six is better, twelve if the work is seasonal. Removing a month clears whatever was in it.
What you must pay every month
Rent or mortgage, loan payments, insurance, subscriptions.
Groceries, fuel, utilities, childcare. Add a twelfth of any annual bill here so the lumpy ones stop ambushing the month they land in.
How conservative is the plan?
Plan on your worst recent month. Anything above it is a bonus.
Measured in months of essential expenses, not months of income. Most people aim for one to three months here, or six if the work is seasonal.
Nothing entered yet. Type the take-home income you received in each of the last few months and the plan fills in as you go.
One of your months was zero, so the lowest-month method plans for zero income. Try the trimmed average if that month was a one-off.
The trimmed average needs at least four months before it can drop a best and a worst one, so it is showing the plain average for now.
Every figure treats your entries as take-home money already received. No tax is calculated here.
Your good-month plan
Pay yourself the baseline every month, bank whatever lands above it, and refill the lean months from that pot.
Your months against the baseline
Everything above the line is money to bank. Everything below it is a month the buffer has to cover.
Irregular income vs. irregular expenses: which problem are you solving?
The phrase "irregular income budget" gets used for two different problems, and most of the calculators you will find online solve the wrong one. If your paycheck is steady but your bills are lumpy (an annual insurance premium, car registration, a dentist visit, new tires), you do not have an income problem. You need a sinking fund: divide each of those annual costs by twelve, add the total to your essential variable spending line above, and set that money aside every month so the bill is already paid for when it lands.
If your income is the thing that moves, this calculator is the right tool. Freelancers, contractors, commission and tip earners, seasonal workers, and anyone paid per project all face the same question: what number is safe to build a month around when no two deposits are the same size? Standard budget calculators ask for "monthly income" as a single figure, which is the exact thing you do not have.
Why the lowest month beats the average
Budget on your average and you are underwater in roughly half your months by construction. That is what an average is. Budget on your lowest recent month and every other month arrives with a surplus, which is a much easier problem to manage than a shortfall.
Take six months of take-home income: 4,200, 5,600, 3,100, 6,400, 4,900 and 3,800. The average is 4,666.67, the lowest is 3,100. With 2,100 of fixed bills and 850 of essentials, the survival number is 2,950. On the lowest-month baseline your safe monthly budget is 150.00 and the good months bank up to 3,300.00. On the average baseline the safe budget looks like 1,716.67, which is a plan that fails in three of those six months. Same numbers, very different year.
The trimmed average is the middle setting. It drops your single best and single worst month before averaging, so one outlier (a client who finally paid three invoices at once, or a month you were ill) does not drag the whole plan with it. It needs at least four months of data to have something to trim. Whatever you pick, plan low and revise up: raising your own budget mid-year is painless, cutting it is not.
Turning good months into a buffer
The method is a loop, not a one-off calculation. Pay yourself the baseline every month, bank everything above it, and top the lean months back up to the baseline out of that pot. The "top-up needed in your leanest month" figure is the size of the transfer you should expect to make; the "typical amount banked per month" is what funds it.
The buffer is sized in months of essential expenses rather than months of income on purpose. A slow month does not need replacing in full, it needs the essentials covered. Keep this pot separate from your emergency fund too. The emergency fund is for the boiler and the broken tooth; the smoothing buffer is designed to be drained and refilled several times a year, which is exactly what you never want an emergency fund to do.
The manual version of all this is two accounts. Income lands in one, and on the same date each month you move your baseline "salary" into the account you actually spend from. What stays behind is the buffer, and it grows without you thinking about it. One note on tax: if you are self-employed, hold your tax share out of each payment before any of this, and enter only what is left. Every figure on this page assumes the money you typed is already yours to spend.
Where to find your last six months of income
The hard part of this calculator is not the arithmetic, it is digging six real numbers out of a bank app that groups deposits by nothing in particular. If you already track your money by hand, the row is sitting there: Budget44's Stats screen has a Last 6 Months range with an income and expense bar chart, which is exactly the sequence this page asks for.
The rest of the loop maps across too. Recurring transactions and recurring budgets hold the fixed side of your survival number, on any of six cadences. The calendar shows recorded against projected activity for the month you are part-way through. And the buffer target belongs in a saving goal: Emergency Fund ships as a preset, but a smoothing buffer deserves its own goal next to it, since the two get spent for very different reasons. All of it stays on the device. No account, no bank connection, and amounts held as integer minor units so the totals stay exact to the cent.
Got your baseline? Download Budget44 and budget a variable income month by month.
Frequently Asked Questions
Common questions about irregular income budget calculator
How do I budget when my income changes every month?
Pick a baseline from your recent months, budget the essentials against that baseline, and treat everything above it as money to bank rather than money to spend. The plan stays the same every month even though the deposits do not, and the buffer absorbs the difference.
Should I budget on my average income or my lowest month?
Lowest month for the plan, average for the forecast. Budgeting on the average guarantees an overspend in every below-average month, which is roughly half of them by construction. This calculator shows both figures so you can see the size of the gap you would be betting on.
How many months of income should I enter?
Three at an absolute minimum. Six is the number worth aiming for, and twelve if your work is seasonal. A six-month window is long enough to catch a normal slow patch without dragging in old rates or clients you no longer have.
How big should a freelancer's income buffer be?
One to three months of essential expenses is the usual target for a smoothing buffer, and it should sit apart from your emergency fund. Push it toward six if your work is seasonal, or if most of it comes from one or two clients.
What is a "survival number"?
The total of the bills and essentials that have to be paid whatever the month brings: housing, utilities, food, transport, insurance, and minimum debt payments. It is the floor your baseline income has to clear before any of the month is discretionary.
What do I do in a month that comes in under my baseline?
Top it up from the buffer you filled in the good months. The "top-up needed in your leanest month" figure on this page is the size of that transfer, based on the worst month you entered.
What if one month was unusually good or unusually bad?
Use the trimmed average. It drops your single best and single worst month, so one freak month does not set the plan for the whole year. It needs at least four months of data; below that it falls back to the plain average.
Does this calculator handle irregular bills as well as irregular income?
No. It budgets a variable income. Lumpy bills such as annual insurance or car registration belong in your monthly essentials as a divided-by-twelve set-aside, so add that monthly figure into the essential variable spending field.