Enter one invoice and see exactly when your cash gets tight.
The amount you're owed, when you expect payment, and your monthly obligations.
A timeline shows when bills are due vs. when payment arrives — and what your balance does in between.
Slide from on-time to 45 days late and watch the impact shift in real time.
When a client pays late, it hits you twice. There's the cash-flow gap — your rent and bills are due before their check lands — and there's the money you could charge for the delay, in late fees or interest. This tool shows the first one, because it's the one that actually catches freelancers off guard: the bills don't wait for the invoice. The second one is worth knowing too, so both are covered below.
Enter one invoice — the amount, the date, and the terms — plus what's in your account and your monthly obligations. It plots your balance over the coming weeks and shows the lowest point it hits before the payment arrives. Then drag the slider from on-time out to 45 days late and watch the dip deepen, and whether it crosses the comfort balance you'd rather not go below.
The point isn't a scary number. It's a date — the day things get tight — so you can see it coming instead of discovering it.
A $5,000 invoice on Net 30 terms, $12,000 in the bank, $4,200 a month in obligations.
One invoice is easy to eyeball. The trouble comes when two or three slip at once, which is the case the tool is really there to make visible.
The other side of late payment is what you're owed for the delay. If your contract or invoice says so, you can usually charge a late fee — often a flat amount, or interest in the range of 1–1.5% per month on the overdue balance. In the UK, the law goes further: you can claim statutory interest of 8% above the Bank of England base rate plus a fixed recovery charge on late commercial payments, even without a clause. Rules vary by country, so check what applies where you are — and put your late-fee terms in writing on every invoice, since that's what makes them stick.
A few things help more than chasing ever does: state your payment terms and a late fee in writing, send the invoice the moment the work is done, ask for a deposit or milestone payments on bigger jobs, and keep enough of a cushion that one slow client doesn't sink the month. If you want to size that cushion, the runway calculator shows how long your savings actually last.
Your income shifts later but your bills don't, so your balance dips in the gap between when payment was due and when it actually arrives. If a fixed cost like rent falls in that window, a late invoice can briefly put you underwater even when the money is technically coming. This tool shows exactly when that dip happens.
Usually yes, if your contract or invoice states it. Many freelancers charge a flat late fee or interest of about 1–1.5% per month on the overdue amount. In the UK you can claim statutory interest of 8% above the base rate plus a recovery fee even without a clause. Check your local rules and put the terms in writing.
A common range is 1–1.5% per month on the unpaid balance, or a flat fee per overdue invoice — whatever your contract specifies. Some countries set statutory rates (the UK's is 8% above the base rate). The enforceable amount is the one you agreed in writing before the work started.
They create a timing gap: expenses keep landing on schedule while income slides later, so your balance drops further than planned and can cross zero or your comfort buffer before the payment clears. The size of the hit depends on the invoice, your balance, and which bills fall in the gap — which is what this calculator maps out.
Put clear terms and a late fee in writing up front, invoice immediately, ask for deposits or milestones on larger projects, and keep a cash buffer so one slow payer doesn't break your month. Seeing the impact ahead of time — and following up the day an invoice goes overdue — beats chasing after the fact.
Yes. Enter the invoice, balance, and obligations in whatever currency you use, and the timeline and lowest-balance figure come back in the same units.
A cash flow calendar, runway forecasting, and budget tracking — built for irregular income. One-time purchase. No subscription.
Been burned by a slow-paying client? Read one freelancer's reckoning with late payments — and the calendar shift that fixed it.
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