Can I afford the iPhone Ultra?

That depends on what's left after your bills, savings, and essentials are protected for the rest of the period — not just whether the card will go through. Enter your numbers above and the calculator shows your safe-to-spend number before and after the purchase, so you can see the actual tradeoff.

There's no universal amount. What matters is what remains after the purchase once your rent, bills, groceries, debt payments, and savings are still covered. A $999 purchase affects someone with $4,000 left very differently than someone with $1,100 left — this calculator measures that difference for your own numbers.

Price alone doesn't answer that. Two people earning the same amount can have very different room to spend, depending on bills, debt, and savings goals. Run the numbers above to see what a $1,000 purchase would actually do to your daily number.

This calculator evaluates the purchase as a single upfront expense, the way paying in full or with a debit card works. A financing or carrier installment plan spreads the cost differently across future months and affects your cash flow in a different way than shown here. We don't provide lending or financing recommendations.

Not automatically. The “What will you actually pay?” field is editable specifically because tax rates, trade-ins, and retailer discounts vary. Enter the total you actually expect to pay, taxes included if you want that precision.

Yes. Enter the amount you actually expect to pay after your trade-in credit is applied in the “What will you actually pay?” field, and the calculator uses that number instead of the phone's full retail price.

The same way the Depo app does: money available, plus confirmed income, minus bills and essentials still due, minus savings and any emergency buffer, divided by the days remaining. That's your safe-to-spend number. Adding the phone as an expense and running the same formula again shows the after number — the difference is the daily impact of the purchase.