Short answer: take your monthly take-home pay, subtract your bills, your subscriptions and what you want to save, then divide what’s left by 30.4. That’s what you can spend on a usual day. To know what you can spend today, divide what’s left of this pay cycle by the days until payday, today included.
That’s the whole method. The rest of this post shows why it works, how to handle the awkward parts (irregular bills, variable pay, a bad week), and a worked example you can copy.
Why a daily number works better than a monthly budget
A monthly budget is easy to set and easy to lose track of. On the 3rd, $2,500 for the month feels like plenty. By the 20th you’re not sure what’s left, and the only way to find out is to add everything up.
A daily number fixes that. It’s one figure you can check in two seconds before you buy something, and it corrects itself: spend a bit more today and every day after gets a little less; spend less and tomorrow gets more. You don’t have to be perfect, you just have to look.
The formula, step by step
1. Start from take-home pay
Use what actually lands in your account each month, after tax and anything your employer deducts. If you’re paid weekly or every two weeks, use only the paydays every month is sure to have (four weekly paydays, two fortnightly ones) and treat the extra paydays some months bring as a bonus for savings.
2. Take out bills
Bills are anything that leaves on a schedule whether you think about it or not: rent or mortgage, car payments, electricity, gas, water, phone, internet, insurance, childcare. Use the monthly amount; for a yearly bill (car insurance, a club membership) divide by 12.
3. Take out subscriptions
Streaming, music, cloud storage, food delivery memberships, the gym, apps. They’re small one by one and big together; most people underestimate them. If you’re not sure of the total, add them up with the subscription cost calculator or read how to find every subscription you pay for.
4. Take out savings, first
Decide what you’ll save this month and treat it as a bill. Saving what’s left at the end of the month rarely works, because nothing is left at the end of the month.
5. Divide by 30.4
What’s left is money for everyday spending: food, groceries, transport, shopping, eating out, the unplanned things. Divide it by 30.4, the average number of days in a month, and you have your daily number.
A worked example
| Per month | |
|---|---|
| Take-home pay | $5,000 |
| Rent | − $1,700 |
| Electricity, phone, internet | − $260 |
| Subscriptions | − $120 |
| Saving | − $800 |
| Left for everyday spending | $2,120 |
| A usual day (÷ 30.4) | $70 |
Now say it’s the 13th of a 30-day month, payday is on the 1st, and you’ve already spent $800 this cycle. You have $1,320 left and 18 days to go, today included: $73 a day from today. Slightly better than usual, because the first twelve days came in under $70.
You can run your own numbers in the daily budget calculator.
Handling the awkward parts
A big day. A wedding gift or a flight doesn’t break the method. The number for the days after simply drops a little. If you know a big spend is coming, set it aside like a bill.
Pay that changes. Use a cautious figure: the lowest month in the last three. Anything above it goes to savings or the next month.
Bills you forget. This is where most budgets fail: the annual renewal you didn’t see coming. Put every yearly charge into step 2 as a monthly amount, or let an app find them for you.
Couples and families. Each person can keep their own number, with shared costs taken out once. See how couples should split bills.
Doing it without the spreadsheet
The formula is simple; keeping it up to date is the hard part. That’s what Nummo does: it finds your bills and subscriptions in your inbox (read-only, no bank login), works out the daily number from your pay and payday, and moves it as you spend. Tap the number in the app and it shows every step of the maths, just like the table above.