How to Build a Monthly Budget in Google Sheets (or Excel)

A budget spreadsheet does one job: show you what’s coming in, what’s going out, and what’s left. You don’t need an app or a subscription to do that well — a plain Google Sheet (or Excel workbook) with five formulas will outlast any trendy budgeting app, and you own it forever.

Here’s the whole thing, start to finish. If you’d rather skip the build, grab the free Monthly Budget Planner — it’s the layout below, already wired up.

1. Set up the four sections

Every working budget has the same four blocks. Put each on its own set of rows:

1. Income — paycheck, side income, anything that lands in your account.
2. Fixed bills — rent, loan payments, insurance: the numbers that don’t move.
3. Variable spending — groceries, gas, eating out: the numbers you actually control.
4. Savings & goals — the amount you pay yourself first.

Use three columns: Category, Planned, Actual. Planned is what you expect; Actual is what really happened.

2. The only five formulas you need

Assume your amounts sit in column C. These work identically in Google Sheets and Excel:

• Total income: =SUM(C2:C5)
• Total spending: =SUM(C8:C20)
• Left to budget: =TotalIncome - TotalSpending (point it at the two cells above)
• Percent of income spent: =TotalSpending/TotalIncome — then format the cell as a percentage.
• Overspending flag: =IF(Actual>Planned, "OVER", "ok") — drag it down the Actual column so problem categories light up on their own.

That IF flag is the trick that makes a spreadsheet beat a budgeting app: the sheet tells you where you blew the plan without you hunting for it.

3. Make it readable at a glance

• Conditional formatting on the “Left to budget” cell: green when positive, red when negative.
• Bold your four section headers so the structure is obvious on a phone screen.
• Freeze the top row (View → Freeze in Sheets) so headers stay put as you scroll.

4. The mistake almost everyone makes

People build a beautiful Planned column and never fill in Actual. The Actual column is the entire point — it’s the feedback loop. Spend 60 seconds every few days dropping in real numbers, and by week three the sheet is doing the thinking for you.

When a spreadsheet isn’t enough

If the friction that kills your budget is typing in transactions, that’s the one job a spreadsheet genuinely can’t automate on its own. A bank-sync tool that imports transactions straight into your sheet fixes exactly that — see budget template vs. budgeting app for when paying for sync is worth it and when it’s just renting something you already own.

These templates are operational tools, not financial advice. Numbers and examples are illustrative.