How to use the monthly cash flow calculator
- Under Income, name each source (for example Salary), enter its Amount ($) after tax, and pick how often it arrives. Press + Add income for more lines.
- Under Expenses, do the same for every bill and habit, including yearly costs such as insurance. Set each line's Type to Need, Want or Saving/debt.
- Read Net cash flow per month at the top, along with your annual total and Savings rate.
- Check Where your money goes for the biggest expenses and the 50/30/20 check for how your spending compares with the guideline. Use the ✕ button to remove a line.
How cash flow is calculated
Net cash flow = Monthly income - Monthly expenses
Amounts that are not monthly are converted first: weekly x 52 / 12, every 2 weeks x 26 / 12, twice a month x 2, quarterly / 3 and yearly / 12. Annual net cash flow is the monthly figure times 12, and the savings rate is net cash flow divided by income. In the 50/30/20 check, needs and wants are the expenses you tagged, and everything left over counts as savings and debt payoff. The 50/30/20 split is a popular budgeting rule of thumb, not a legal or official standard. For a blank budget worksheet, see the CFPB Your Money, Your Goals toolkit.
Worked example with the default numbers
Income is $6,000 of Salary plus $500 of Side income, which is $6,500.00. Expenses are Housing $2,000, Food $600, Transport $400 and Other $800, which is $3,800.00. Net cash flow is $6,500.00 - $3,800.00 = $2,700.00 a month, or $32,400.00 a year, a savings rate of $2,700 / $6,500 = 41.5%. Housing takes 30.8% of income. Needs (housing, food, transport) are $3,000.00 or 46.2%, wants are $800.00 or 12.3%, and savings are 41.5%, well above the 20% guideline.
Limits and edge cases
- Enter take-home pay, not gross. If income varies, use a conservative monthly average, and keep one-off windfalls out of the list.
- Negative cash flow shows in red with how much more you spend than you earn. Amounts must be zero or positive, so enter refunds as a smaller expense.
- Count minimum debt payments as Need and extra payoff as Saving/debt. For the big picture, use the net worth calculator or see whether your debts fit your pay with the debt-to-income calculator.
- For comparison, the Bureau of Labor Statistics found US households spent an average of $78,535 in 2024, about $6,545 a month, with 33.4% going to housing and 17.0% to transportation. Your numbers will differ with income, location and family size.
- Once you have money left over, plan it with the savings goal calculator and the emergency fund calculator.
Cash flow questions people ask
What is personal cash flow?
Money coming in each month minus money going out. Positive cash flow can go to savings, investing or paying down debt. Negative cash flow means you are covering the gap with savings or credit.
Should I use gross or take-home pay?
Use take-home pay, because taxes and payroll deductions never reach your account. If you are self-employed, set aside money for taxes first and enter what is left.
How often should I check my cash flow?
Monthly at minimum. A quarterly review catches creeping subscriptions, and a yearly review shows seasonal patterns such as holiday spending and tax refunds.
What is the 50/30/20 rule?
A rule of thumb that splits take-home pay into about 50% needs, 30% wants and 20% savings and debt payoff. It is a starting point, and high housing costs can make it hard to reach in some cities.
Is cash flow the same as free cash flow?
No. Free cash flow is a business measure, operating cash flow minus capital expenditures. This calculator tracks personal or household money in and out.
Sources: Consumer Financial Protection Bureau, Your Money, Your Goals toolkit. U.S. Bureau of Labor Statistics, Consumer Expenditures, 2024.