Monthly Cash Flow Calculator
How to Use This Calculator
- 1
Enter regular income and expenses
Use Monthly Income ($) and Monthly Expenses ($) for recurring amounts in a typical month.
- 2
Add irregular items for this month
Enter One-Time Income ($) and One-Time Expenses ($) only for extra amounts received or paid this month. The calculator includes them in this month's totals.
- 3
Review cash flow and ratios
Check Net Monthly Cash Flow, Savings Rate, Expense-to-Income Ratio, and Annualized Cash Flow. The annualized result multiplies this month's net cash flow by 12, including one-time items.
Example Calculation
A person receives $4,000 in regular monthly income and $500 in one-time income, with $3,000 of regular expenses and $200 of one-time expenses.
Monthly Income ($)
4,000
Monthly Expenses ($)
3,000
One-Time Income ($)
500
One-Time Expenses ($)
200
Results
Net Monthly Cash Flow
$1,300
Total Monthly Income
$4,500
Total Monthly Expenses
$3,200
Savings Rate
28.9%
Expense-to-Income Ratio
71.1%
Annualized Cash Flow
$15,600
Tips
Remove one-time items to see recurring cash flow
Set One-Time Income ($) and One-Time Expenses ($) to $0. With the regular inputs unchanged, monthly cash flow is $1,000 and its annualized value is $12,000.
A $500 one-time repair expense lowers this month's cash flow by $500
Change One-Time Expenses ($) from $200 to $700 to test the effect of a larger irregular bill. Net monthly cash flow falls from $1,300 to $800.
A positive month does not guarantee a positive year
Use conservative income and include less frequent bills in the month they occur. Compare several months rather than treating one unusually strong month as your normal result.
What this calculator estimates
Monthly cash flow is income received during a period minus expenses paid during that period. This calculator includes regular and one-time amounts in the same month's result, but it does not model account balances, unpaid invoices, taxes, or the timing of transactions within the month.
How the calculation works
Total income = monthly income + one-time income
Total expenses = monthly expenses + one-time expenses
Net cash flow = total income − total expenses
Savings rate = net cash flow ÷ total income × 100
Expense ratio = total expenses ÷ total income × 100
Annualized cash flow = net cash flow × 12
For the example, total income is $4,000 + $500 = $4,500, and total expenses are $3,000 + $200 = $3,200. Net cash flow is $4,500 − $3,200 = $1,300. The savings rate is $1,300 ÷ $4,500 × 100 = 28.9%, while the expense ratio is $3,200 ÷ $4,500 × 100 = 71.1%. Multiplying $1,300 by 12 gives an annualized cash flow of $15,600.
The savings rate here is net cash flow divided by income. It is not a retirement contribution rate or a measure of investment returns.
Separate recurring cash flow from unusual months
One-time items can make a month look stronger or weaker than your regular finances. Keep them in the result when reviewing the actual month, then run a second calculation with one-time fields set to zero to understand the recurring pattern.
| Scenario | Total income | Total expenses | Net cash flow |
|---|---|---|---|
| Regular amounts only | $4,000 | $3,000 | $1,000 |
| One-time income of $500 and expense of $200 | $4,500 | $3,200 | $1,300 |
| Regular amounts plus a $700 one-time expense | $4,000 | $3,700 | $300 |
For business use, compare cash flow across periods and account for when customers pay and suppliers are due. The SBA's manage-your-finances guidance covers practical financial management beyond a single-month surplus calculation.
When to use a different calculator
- Focus on cash generated by business operations → operating cash flow calculator
- Review personal income and spending patterns → personal cash flow calculator
- Estimate a small business's monthly cash flow → small business cash flow calculator
- Calculate free cash flow after business investment spending → free cash flow calculator
Frequently Asked Questions
What is monthly cash flow?
Monthly cash flow is income received during a month minus expenses paid during that month. A positive result is a surplus for that period; a negative result means expenses exceeded income.
How do I calculate the savings rate?
1. Add regular and one-time income. 2. Subtract regular and one-time expenses to find net cash flow. 3. Divide net cash flow by total income and multiply by 100. A negative cash flow produces a negative savings rate.
Does annualized cash flow predict what I will save this year?
No, it multiplies this month's net cash flow by 12 and assumes the month repeats. Because it includes one-time income and expenses, use recurring monthly figures or a full-year cash-flow plan for a more representative projection.
Should I include taxes in income or expenses?
Use a consistent basis and do not count the same tax twice. For a household budget, take-home income and expenses paid from that income are usually easier to compare; for a business, use the basis that matches your bookkeeping and cash-flow purpose.
How is business cash flow different from profit?
Cash flow tracks money moving into and out of a business, while profit is calculated under accounting rules and can include non-cash items or revenue not yet collected. The U.S. Small Business Administration's finance guidance explains the role of tracking business finances; use a dedicated business cash-flow tool for operating details.