How is this different from profit?

Profit is revenue minus recognized expenses. Cash is what's actually in the bank on a given day — the two rarely match.

Why can a profitable month still run out of cash?

Because of timing. Inventory is paid now, payouts arrive later, and taxes come due in a lump. Profit ignores when the money moves; cash doesn't.

What is a safe spending amount?

It's your projected ending cash minus the buffer you want to keep untouched. Anything above that line is what you can commit without dipping into reserves.

What should my cash buffer be?

Many small sellers keep one to three months of fixed costs. Pick a figure you can actually reach, then raise it as the business grows.

Do I include owner draw?

Add it under Other if you take money out of the business — it's real cash leaving the account.

Cash Flow Calculator

Project ending cash for a month or campaign after all revenue and expenses, and see whether you clear your cash buffer.

Free calculator
Instant estimate
No signup needed
Beginner friendly

Display currency

Enter every amount in the same currency. This selector only changes the symbol shown — it does not convert exchange rates.

Starting position

Starting cash ($)

Expected sales revenue ($)

Expected expenses

Product costs ($)

Advertising ($)

Subscriptions / software ($)

Shipping / fulfillment ($)

Estimated taxes ($)

Other expenses ($)

Optional

Cash buffer goal ($)

How much cash you want to still have at the end.

Total income

$8,000.00

Total expenses

$5,150.00

Ending cash

$7,850.00

Cash shortfall

$0.00

Safe spending amount

$4,850.00

Above your buffer goal

Ending cash covers your buffer with $4,850.00 available to reinvest or save.

All calculations are estimates based on average platform fees. Real profits may vary depending on category, ads, and shipping.

This calculator is for planning estimates only. It is not legal, tax, financial, or platform-policy advice.

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How to use this calculator

Enter your numbers in each field above — the calculator updates instantly as you type, so there's nothing to submit.
Use your real figures when you have them, or sensible estimates while you're planning. If a field doesn't apply, leave it at zero.
Compare the results, then change one input at a time to see how each lever (price, cost, fees, volume) moves the outcome.

When to use this calculator

At the start of a month, when you want to know what you can safely spend.
Before committing to an inventory order, ad budget, or new subscription.
When profit looks fine on paper but the bank balance keeps dropping.
When you're setting or reviewing a minimum cash buffer for the business.

Formula

Ending cash = Starting cash + Revenue − (Product + Ads + Subs + Shipping + Taxes + Other) · Safe spend = Ending − Buffer

Worked example

$5,000 start, $8,000 revenue, $5,850 expenses, $3,000 buffer.

Ending = 5000 + 8000 − 5850 = $7,150
Safe = 7150 − 3000 = $4,150

Answer: $7,150 ending, $4,150 above buffer

How it works

Cash flow answers the only question that matters when money's tight: will I still have cash at the end of the month? A profit forecast isn't the same — profit can be positive while cash goes negative because of timing.

Expert tips

Set a buffer you'd be comfortable never touching — one month of fixed costs is a common starting point.
Enter expected sales conservatively. Cash planning is the one place where optimism is expensive.
Include the tax you're setting aside as an expense, even if the payment isn't due yet — that money isn't spendable.
If safe spend comes out negative, the fix is timing: delay a purchase, shorten payout delays, or trim a recurring cost.

How to interpret your results

Dollar values are shown per sale, per order, or per item unless a result is explicitly labelled monthly, weekly, or daily.
Percentages (margin, ROI, conversion rate) are easier to compare across products and price points than raw dollars — use them when you benchmark.
A positive result means you're ahead after the costs and fees you entered. A negative result means the current numbers don't work — change a lever (raise price, cut a cost, lower ad spend) and recalculate.
Treat the output as a planning estimate, not a guarantee. Fees, taxes, and conversion rates shift over time — re-run the numbers whenever a key input changes.

Common mistakes

Confusing profit with cash.
Forgetting taxes and quarterly costs.
Setting a buffer that's larger than your cash on hand.

Go deeper with plain-English guides on the same topic.

FAQ

How is this different from profit?: Profit is revenue minus recognized expenses. Cash is what's actually in the bank on a given day — the two rarely match.
Why can a profitable month still run out of cash?: Because of timing. Inventory is paid now, payouts arrive later, and taxes come due in a lump. Profit ignores when the money moves; cash doesn't.
What is a safe spending amount?: It's your projected ending cash minus the buffer you want to keep untouched. Anything above that line is what you can commit without dipping into reserves.
What should my cash buffer be?: Many small sellers keep one to three months of fixed costs. Pick a figure you can actually reach, then raise it as the business grows.
Do I include owner draw?: Add it under Other if you take money out of the business — it's real cash leaving the account.

Why trust this calculator?

This tool uses standard mathematical formulas and commonly accepted calculation methods, shown openly in the Formula section above so you can verify the math yourself. Results are estimates based on the information you enter and do not account for every individual circumstance. For important financial, tax, legal, medical, or business decisions, please double-check with a qualified professional before acting on the numbers.

What to calculate next

After projecting this month's cash, stress-test how long your reserves last, confirm the profit behind the cash, and set aside what you'll owe in tax before you spend the surplus.

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