Beth

1. Balance and payday. Your banking app balance, after pending payments (not "available to spend" if that includes an overdraft; overdrawn? use a minus), and the date your pay lands (weekend or bank holiday: usually the working day before).

• Only paid weekly or fortnightly, and payday's just days away? Use the payday after, and count this payday's pay in step 3.
• Two pays, like monthly and weekly jobs, or a wage and Universal Credit? Use the payday for the pay your rent or mortgage comes from, and put the other pay in step 3.
• No fixed payday (self-employed, app or agency work)? Pick a date to look ahead to, like the day after your next big bill, or two weeks away, and in step 3 count only money you've already earned.
• Some of it has to last past payday, like a student loan for the rent in the months ahead? Take that part off.

2. Bills before payday. Direct Debits, standing orders and subscriptions, with dates and amounts. Leave out anything already gone, or due on payday or after. Date passed but not gone (weekends, bank holidays)? Use today's date.

3. Money in before payday. Money you're sure of, with the date it lands: a refund, Universal Credit, Child Benefit, a second wage, or cash-in-hand pay, on the day you get it. Not your payday pay, or money already in your balance. Using the payday after (step 1)? Count this payday's pay here.

4. Daily spend. Last week's card and cash spending (not step 2's bills), divided by 7.

5. Find your lowest point. Your balance is lowest the day before payday or before money lands, so do one sum for payday and one for each date money lands:

balance + money landing before that date − bills due before that date − daily spend × days

Days is that date minus today's: the 18th to the 28th is 10 days. The lowest answer is your lowest point, on the day before its date.

• Above zero? It looks fine on these figures, ideally with £50 spare.
• Below zero, with an arranged overdraft? You'd be in it. Short by more than your limit? The difference is how far past it you'd go.
• Below zero, no overdraft? That's how short you'd be.

Today is the 18th and payday is the 28th. Balance £300, daily spend £20. Bills: phone £20 on the 19th, energy £85 on the 20th, car insurance £150 on the 21st, streaming £11 on the 24th. Money in: a £40 refund on the 22nd, and £150 a friend owes you on the 23rd.

• Payday, the 28th (28 − 18 = 10 days): £300 + £190 − £266 − 10 × £20 = £24
• The £150, on the 23rd (5 days): £300 + £40 − £255 − 5 × £20 = −£15. The £40 has landed by then; the £150 hasn't.
• The £40, on the 22nd (4 days): £300 − £255 − 4 × £20 = −£35. Nothing has landed yet.

Lowest: −£35, so you'd be short by £35 around the 21st, even though you end up £24 to the good.

Two ways round it: ask to move the £150 insurance to payday, and your lowest point becomes £115. Or spend £11.25 a day instead of £20, and it's exactly £0: you make it, but with nothing spare.

• Move a bill date. Ask the company if it can move the payment to just after payday. Ask before it's due.
• Pause a subscription. Pause or cancel one you can live without before it next renews.
• Talk to the lender early. If a loan, card or bill payment won't be covered, contact them before the payment is missed, not after.
• Priority bills first. If you can't pay everything, priority bills, such as rent or mortgage, council tax, gas and electricity, and your TV Licence, come first. MoneyHelper's Bill prioritiser explains which and why.
• Thinking of borrowing to cover the gap? Talk to one of the free services below first.