Why is "can I afford it" hard to answer?
Because the number you look at is the wrong one. The balance in your account includes money already promised to rent, bills and subscriptions. A purchase can be far smaller than your balance and still leave a bill short two weeks later.
The useful comparison is against money that is actually free: what is left this month after the committed things are set aside, spread over the days that are left. The safe-to-spend guide explains how to work that out.
What are the three questions?
- Does it fit today? Compare the price with today's safe-to-spend number. If the price is below it, buying it leaves every later day untouched.
- How many days does it cost? If it does not fit today, divide the price by your daily number. If you can safely spend $40 a day, a $120 jacket costs three days. Then ask whether the jacket is worth three days of everything else.
- Does it survive 48 hours? Wanting something is strongest in front of it. Wait two days. Many wants fade in that time, and the ones that last are more likely to be worth it.
If the price is more than all the free money left this month, the honest answer is not this month. Plan it for next month instead of borrowing for it.
What does this look like with real numbers?
Illustrative numbers: it is the 12th, $760 is left for everyday spending after bills, and 19 days remain including today, so $760 / 19 = $40 a day.
| Item | Price | Days it costs | Each remaining day after it | Verdict |
|---|---|---|---|---|
| Lunch out | $18 | Fits today | $40.00, today $22 left | Buy it |
| Concert ticket | $95 | 2.4 | $35.00 | Wait 48 hours |
| New headphones | $350 | 8.8 | $21.58 | Plan it for next month |
The fourth column is the one to read. After the headphones, every day for the rest of the month drops from $40 to ($760 - $350) / 19 = $21.58. That is the real price of buying them now.
Does paying by card or in installments change the answer?
No. A credit card moves the payment later, but the money still has to come out of a future day's budget, with interest if you do not pay the statement in full. Splitting a price into installments does the same thing in smaller pieces. Count the whole price in the check, or at least every installment due before money next arrives, and the answer stays honest.
If the purchase is in another currency, convert it before you compare. A price that looks small in a foreign currency can be several days of spending in your own.
How does Tally help with this?
Tally keeps the daily number for you, and Tally Lens checks a price against it. Point the camera at a price tag, a menu or a screen, or type the price, and Lens answers in words: it fits today and how much is left today after it, or how many days of everyday money it takes and what each remaining day drops to, or that it is more than this month has left. Abroad, the price is converted into your own currency first. The reading happens on the iPhone and nothing is uploaded. Lens opens from Home, or with Check a price in Siri, Shortcuts or the Action button.
If you are not sure, hold it. Hold keeps the purchase for 48 hours, then asks once whether you still want it, in the daytime rather than the middle of the night. What you let go of adds to a running total of what you walked away from this year. Lens and Hold are free.