Free tool

Cash flow calculator

Put in the cash in the bank today and what comes in and goes out each month. You get the month cash runs short, and a chart of every month until then.

Example numbers. Type over them with yours.

All business accounts, as of today.

Customer payments and any other deposits.

Payroll, rent, bills, loan payments, owner draws.

Your numbers stay in this browser. Nothing you type is sent or saved.

The answer

Cash runs short in August 2027.

months of cash, this month included
10
net cash flow this month
−$13,000

Cash in the bank, month by month

Balance at the end of each month, starting today. Hover or tap for a month.

Cash in the bankBelow zeroMonth cash runs short
−$200K−$100K$0$100K$200KNowDec ’26Mar ’27Jun ’27Sep ’27Dec ’27Mar ’28Jun ’28Sep ’28Runs short · Aug ’27
See it month by month
MonthMoney inMoney outCash at month end
Oct 2026$82,000$95,000$127,000
Nov 2026$82,000$95,000$114,000
Dec 2026$82,000$95,000$101,000
Jan 2027$82,000$95,000$88,000
Feb 2027$82,000$95,000$75,000
Mar 2027$82,000$95,000$62,000
Apr 2027$82,000$95,000$49,000
May 2027$82,000$95,000$36,000
Jun 2027$82,000$95,000$23,000
Jul 2027$82,000$95,000$10,000
Aug 2027$82,000$95,000−$3,000
Sep 2027$82,000$95,000−$16,000
Oct 2027$82,000$95,000−$29,000
Nov 2027$82,000$95,000−$42,000
Dec 2027$82,000$95,000−$55,000
Jan 2028$82,000$95,000−$68,000
Feb 2028$82,000$95,000−$81,000
Mar 2028$82,000$95,000−$94,000
Apr 2028$82,000$95,000−$107,000
May 2028$82,000$95,000−$120,000
Jun 2028$82,000$95,000−$133,000
Jul 2028$82,000$95,000−$146,000
Aug 2028$82,000$95,000−$159,000
Sep 2028$82,000$95,000−$172,000

How to read the result

The calculator starts with the cash in your bank account today. Each month it adds what comes in and takes out what goes out. The first month the balance would end below zero is the month cash runs short.

Months of cash counts the full months your cash covers, this month included. If money in is equal to or more than money out, cash does not run short, and the chart shows how it builds.

Net cash flow is money in minus money out for the month. When it is negative, that gap is your burn: the amount the bank balance falls each month.

Use cash, not the P&L. A sale you have invoiced but not collected (accounts receivable) is not cash until it lands. Loan payments, owner distributions and equipment purchases are cash out, even though some of them never show up as expenses on the P&L.

What to do when cash runs short

  1. 01

    Check the inputs

    Pull the last three months of bank statements and average the deposits and the withdrawals. A guess about money out is usually low.

  2. 02

    Collect faster

    Look at accounts receivable: invoices out, not yet paid. Bill sooner, follow up sooner, and ask for deposits on big jobs.

  3. 03

    Pay on purpose

    Know which bills are fixed and which can move. Talk to a vendor before a bill is late, not after.

  4. 04

    Fix the gap before you borrow

    A line of credit buys time. It does not fix a month where more goes out than comes in.

  5. 05

    Run it again

    Change money in or money out to match the plan and watch the month move. Then talk to your banker early, while you still have choices.

This is a straight-line estimate. Real months are lumpy: seasons, annual bills, tax payments, a big customer who pays late. A cash flow forecast built from your books follows all of that.

Questions

How do I calculate cash flow?

Cash flow for a month is the money that came in minus the money that went out. Start with the cash in the bank, add what comes in, take out what goes out, and you have the balance at the end of the month. This calculator repeats that for every month ahead.

What is cash runway?

Runway is how long your cash lasts if money in and money out stay where they are. When you spend more than you take in, divide the cash in the bank by the monthly gap. The calculator does the same math month by month and names the month the money runs out.

What should I put in money in and money out?

Use cash, not the P&L. Money in is what lands in the bank: customer payments, loan proceeds, any other deposit. Money out is everything that leaves: payroll, rent, vendors, loan payments, taxes and owner draws. Your last three months of bank statements are the easiest place to start.

When should I add monthly growth?

When money in or money out moves in a steady direction. If sales grow each month, or a new hire raises payroll, a growth rate gets closer than a flat number. Use a minus sign for money that is falling.

Is my information saved?

No. The math runs in your browser. Nothing you type is sent to us or saved, and there is no sign-up.

Is this a cash flow forecast?

It is a quick estimate. A real forecast follows your actual bills, payroll dates, how fast customers pay and your seasons, often week by week. If the answer here worries you, that is a good time to build one.

Want a forecast built from your books?

A free 30-minute walk through your numbers. Send the last two years of P&Ls and a balance sheet first, and you leave with what we see and what we'd recommend. If we're not the right fit, we'll tell you.

Book a Walkthrough