Cash Flow Calculator
Project your cash balance month by month and see if and when the money runs out.
Your cash
Filled in with example values. Replace them with your own.
Optional
Cash in and cash out grow (or shrink, with a negative number) by a percentage every month.
Currency symbol
Results update as you type.
Result
Cash after 12 months: $9,922.15 (starting from $10,000.00)
Cash after 12 months
$9,922.15
- Total cash in
- $127,337.01
- Total cash out
- $127,414.86
- Net cash flow
- −$77.85
- Lowest balanceMonth 6
- $4,488.14
Month by month
| Month | In | Out | Net | Balance |
|---|---|---|---|---|
| 1 | $8,000.00 | $9,500.00 | −$1,500.00 | $8,500.00 |
| 2 | $8,400.00 | $9,690.00 | −$1,290.00 | $7,210.00 |
| 3 | $8,820.00 | $9,883.80 | −$1,063.80 | $6,146.20 |
| 4 | $9,261.00 | $10,081.48 | −$820.48 | $5,325.72 |
| 5 | $9,724.05 | $10,283.11 | −$559.06 | $4,766.66 |
| 6 | $10,210.25 | $10,488.77 | −$278.52 | $4,488.14 |
| 12 | $13,682.71 | $11,812.06 | $1,870.65 | $9,922.15 |
How it’s calculated
Month 1 net cash flow
$8,000.00 − $9,500.00 = −$1,500.00
Month 1 closing balance
$10,000.00 + −$1,500.00 = $8,500.00
Each later month
Previous balance + that month’s net cash flow = $9,922.15 after month 12
How the cash flow calculator works
Enter the cash you have today, the cash you expect to receive each month and the cash you expect to pay out. The calculator projects the balance month by month: each month starts with the previous month’s closing balance, adds the cash in and takes off the cash out. It flags the first month the balance would fall below zero and the lowest point it reaches.
Turn on monthly change to let cash in and cash out grow or shrink by a steady percentage.
The formula
Cash in (month k) = Cash in × (1 + Change in %)^(k − 1)
Cash out (month k) = Cash out × (1 + Change out %)^(k − 1)
Net cash flow = Cash in − Cash out
Closing balance = Opening balance + Net cash flow
Worked example
A business starts with 10,000, receives 8,000 and pays out9,500 in the first month. Cash in grows 5% a month and cash out2%:
- Month 1: 8,000 − 9,500 = −1,500, leaving 8,500
- Month 2: 8,400 − 9,690 = −1,290, leaving 7,210
- Month 3: 8,820 − 9,883.80 = −1,063.80, leaving 6,146.20
- Month 7: cash in (10,720.77) passes cash out (10,698.54) for the first time
- The lowest balance is 4,488.14 in month 6, and the year ends at 9,922.15
Assumptions and limitations
- Amounts are worked in whole cents; each month’s cash in and cash out are rounded half up.
- The balance is checked at the end of each month. Within a month it could dip lower if payments go out before money comes in.
- Growth is a steady percentage every month. Real sales and costs rarely move so evenly.
- Interest, tax timing and one-off payments are only included if you build them into your monthly figures.
Frequently asked questions
What is the difference between cash flow and profit?
Profit compares sales with costs when they are earned or incurred. Cash flow follows the money itself: when customers actually pay and when you actually pay your bills. A profitable business can still run out of cash if customers pay late or stock has to be bought in advance.
What should I count as cash in?
Money that reaches your account in the month: customer payments, loans received, grants, money you put in. An invoice that has not been paid yet is not cash in.
What should I count as cash out?
Everything you pay in the month: rent, wages, suppliers, loan repayments, tax payments, equipment. Include one-off payments by averaging them, or project those months separately.
What does it mean when cash runs out?
The balance would fall below zero in that month. In practice that means an overdraft, missed payments or the need for more funding, so it is the month to plan for well in advance.
Can I model seasonal sales?
Not month by month: this calculator applies one steady percentage change. For a seasonal business, try a few runs with different figures, or use average monthly amounts.