Most money topics, from budgeting to borrowing, come back to a simple question: how much comes in, how much goes out and when. This lesson names the parts of that question so the rest of the course has a shared vocabulary. The numbers in the examples are invented for illustration.
Income: gross and net
Income is money received. For many people the main source is pay from a job, but income can also come from self-employment, benefits, child support, rental property, interest or a side business.
Pay is usually described in two ways. Gross income is the amount earned before anything is taken out. Net income, often called take-home pay, is what actually arrives in a bank account after deductions. Common deductions include federal and state income tax withholding, Social Security and Medicare taxes, and anything a worker has signed up for through an employer, such as health insurance premiums or retirement plan contributions.
The gap between the two can be large. A job advertised at $3,200 a month might bring home noticeably less once withholding and benefit premiums are subtracted. Because bills are paid from what arrives, many people plan around net income rather than the advertised figure.
Income also differs in how predictable it is. A salary paid on the same dates each month is steady. Hourly work with changing shifts, tips, commissions and freelance payments can rise and fall. When income varies, one common approach is to look at several months together and plan around the lower months, so a slow month is less of a surprise.
Expenses: fixed, variable and occasional
Expenses are money going out. Sorting them into groups makes them easier to see.
- Fixed expenses stay roughly the same each month: rent or a mortgage payment, a car payment, an insurance premium paid monthly, a phone plan.
- Variable expenses change from month to month: groceries, fuel, utilities that depend on the weather, eating out, entertainment.
- Occasional (or irregular) expenses don't arrive every month but are still predictable: a yearly car registration, holiday gifts, school supplies, a twice-a-year insurance bill, a regular medical visit.
Occasional expenses are the ones that tend to cause trouble, because they are easy to forget until the bill arrives. One technique people use is to add up the year's irregular costs and divide by twelve, which turns them into a monthly figure that can be set aside.
Another common distinction is between needs and wants. Housing, basic food, utilities and getting to work are usually treated as needs; streaming services and restaurant meals as wants. The line isn't always sharp, and different households draw it in different places. The labels are a tool for thinking, not a judgment.
Cash flow: putting it together
Cash flow is the movement of money in and out over a period of time. Subtracting expenses from net income for the same period shows whether the period ended with money left over (positive cash flow) or with a shortfall (negative cash flow) that had to be covered by savings or borrowing.
Here is a sample month, with invented figures:
- Net income: $2,700
- Fixed expenses: rent $1,100, car payment $280, phone $60, insurance $120 (total $1,560)
- Variable expenses: groceries $420, fuel $140, utilities $130, other spending $250 (total $940)
- Occasional expenses set aside: $1,200 a year divided by 12, or $100
Total expenses come to $2,600, so this sample month has a positive cash flow of $100. If the variable spending had been $200 higher, the same month would have ended $100 short.
Notice how much of the picture depends on the variable categories. Fixed costs are known in advance, so they rarely explain a surprise. When a month ends differently than expected, the difference usually sits in groceries, fuel, utilities or "other" spending. That is why many people start by tracking those categories for a month or two before trying to plan them, a step the Budgeting That Sticks course covers in detail.
Timing matters too
A month can balance on paper and still feel tight, because cash flow is also about when money moves. If pay arrives on the 15th and the 30th but rent is due on the 1st, the first half of the month carries most of the bills. Lining up due dates against paydays on a calendar is a simple way to see these pressure points. Some lenders and service providers let customers change a due date, which is one reason people sometimes ask.
Why these ideas come first
Budgeting is planning cash flow ahead of time. Saving is directing part of a positive cash flow somewhere specific. Borrowing is one way a negative cash flow gets covered, at a cost. The rest of this course, and the other courses, build on these three words: income, expenses and cash flow.
Sources and further reading
- Consumer Financial Protection Bureau, Your Money, Your Goals toolkit
- U.S. Financial Literacy and Education Commission, MyMoney.gov