What can I safely spend?
Your balance is not your spending money. This works out the most you can spend today while staying above your buffer for as long as you choose.
The floor you never want to cross.
Max safe spend
$2,100
That keeps you above your buffer through Thu 17 Dec. The tightest day is Sun 18 Oct - Bills.
Keep going
This calculator stays free and works without an account. The app adds your real bills, paydays, cards and loans.
The number your bank balance refuses to tell you
Every account balance is a mix of two very different kinds of money: cash that is already spoken for by bills arriving in the next few weeks, and cash that is genuinely free. Banks show you one number for both, which is why an account can look healthy on the fourteenth and be overdrawn on the second.
The maximum safe spend fixes that by asking a sharper question: if I take an amount out today, what happens to every day after it? Because a single spend shifts the entire future curve downward by the same amount, the answer is straightforward - find the lowest closing balance between now and your horizon, subtract the buffer you want to protect, and whatever remains is genuinely yours to spend.
Choosing a horizon that matches the purchase
A coffee needs no horizon. A four-thousand-dollar roof repair needs at least ninety days, because that window contains quarterly insurance, an annual renewal, and possibly a month where a bill lands twice. The longer the horizon, the more conservative and the more honest the answer becomes.
- Until payday (7 to 14 days): day-to-day spending decisions.
- 30 days: a normal purchase you would rather not regret.
- 60 to 90 days: repairs, travel, deposits, anything large.
Buffer versus zero
Running to zero is technically solvent and practically miserable: one forgotten charge turns into an overdraft fee, and a fee on a tight week can cascade. A buffer of a few hundred dollars absorbs ordinary variance - a bigger grocery shop, a price rise, a bill that lands a day early. Set the buffer to zero only to see the theoretical ceiling, then decide against it deliberately rather than by accident.
Turning a safe number into a decision
If the amount you want exceeds the safe amount, you have three honest levers: delay the purchase past the next payday, shrink it, or move a bill so the tight day stops being tight. Seeing the binding day named - the specific date and bill that limits you - usually makes the right lever obvious in seconds.
Lastwell keeps this calculation running against your live numbers, including cards and loans, so the answer is always one question away.
Frequently asked questions
- How much can I safely spend right now?
- The safe amount is the lowest closing balance you are projected to hit between today and the end of your horizon, minus the buffer you want to keep. Spending today lowers every future day by the same amount, so that lowest point is what limits you.
- Why not just look at my account balance?
- Your balance today includes money that is already promised to rent, insurance and card payments. The account can show two thousand dollars while only three hundred of it is genuinely uncommitted.
- What is a safety buffer?
- A floor you refuse to go under - often a few hundred dollars - so an unexpected charge does not overdraft you. Set it to zero if you want the absolute maximum instead.
- How far ahead should I look?
- Thirty days answers 'can I afford this until payday'. Sixty to ninety days is better for a repair or a trip, because it includes quarterly and annual bills that a short window misses.
- Does spending on a credit card change the answer?
- Yes, but later. A card spend hits your cash on the payment due date, not the purchase date, which is exactly how Lastwell models it in the full app.