Guide · 2026-10-16

How to build a monthly budget in Google Sheets

A plain-language way to set up a monthly budget spreadsheet in Google Sheets: list your income, group your spending, plan each category and check plan against actual.

A monthly budget doesn't have to be complicated. At its core it is a short list of what you expect to earn, a list of what you plan to spend it on, and a way to compare the plan with what really happened. Google Sheets is a good place to do it: it is free, it works on your phone, and your numbers stay in your own account instead of being handed to a bank-linked app.

This guide shows how to build a monthly budget spreadsheet from scratch, and where a ready-made template saves you the setup.

Step 1: Decide what "a month" means for you

Most people budget by calendar month. If you are paid weekly, every two weeks or twice a month, you can still budget monthly and just add up the paychecks that land inside it. Some households find it easier to budget by paycheck instead, because bills are due on specific dates and a paycheck either covers the next few or it doesn't. We'll come back to that below.

Start with a single month. You can copy the setup for later months once it works.

Step 2: List your income

Write down the money you realistically expect to receive this month: wages, side income, regular payments to you. Use the amount that actually reaches your account, not the number before deductions. If your income varies, base the plan on a cautious figure, such as your lowest recent month, and treat anything above it as a bonus to assign later.

Keep income on its own section or its own tab. It is the starting number every other decision depends on.

Step 3: List your categories and group them

Next, list the things you spend money on. Aim for categories you will recognise in your bank statement, such as rent or mortgage, groceries, utilities, transport, phone, insurance, eating out and subscriptions.

Then group them. A simple and popular way is four groups:

Needs: housing, groceries, utilities, transport, insurance, minimum debt payments.
Wants: eating out, entertainment, hobbies, subscriptions you could live without.
Savings: emergency fund, sinking funds for things you know are coming, other goals.
Debt: payments above the minimum.

Groups are useful because they show the shape of your spending at a glance. You do not have to follow any particular percentages. The point is to see where the money goes and decide if you are happy with it.

Step 4: Give every dollar a job

This is the heart of a plan. Type a planned amount next to each category until your total plan matches your income. A helpful check is a single cell called "left to assign" that equals income minus planned spending. When it reaches zero, every dollar has a job, including the dollars that go to savings. If it goes negative, you've planned to spend more than you earn, and now is the time to adjust, not at the end of the month.

If you like a weekly budget, divide the monthly plan for flexible categories like groceries and eating out into four or five weekly amounts. Fixed costs like rent stay as one monthly line.

Step 5: Log what you actually spend

Plans only help if you compare them with reality. Make a simple transactions table with these columns: date, description, category, amount and type (income, expense, transfer, savings or debt payment). Add a row whenever you spend or get paid. A spending tracker like this takes a minute or two a few times a week, and it is more reliable than trying to remember at month end.

Two tips keep this sustainable. First, log in batches if you prefer: every few days, go through your bank app or receipts and enter them together. Second, use the same category names as your plan, so the totals can be matched automatically.

Step 6: Compare plan with actual

Now add a summary: for each category, the plan, the spent-so-far, what's left and the percent used. In Google Sheets you can use SUMIFS to add up all transactions for a category in a given month. Add a simple flag next to each line, such as a warning when you have used 80 percent of a category and a stronger one when you go over. Seeing a flag in the middle of the month is what lets you change your behavior while it still matters.

Step 7: Look at the year

After a few months, add a year view that shows each category by month. Patterns appear: the quarter where insurance is due, the month holiday spending jumps, the category that is always a little over. Those patterns turn into better plans. If you are getting ready for a new year, it also makes a handy base for a 2027 planner, because you can start the new year's plan from what you really spent this year rather than guesses.

What if you get paid every other week?

Budgeting by paycheck is a good fit for biweekly or weekly pay. Instead of one monthly pot, you assign each paycheck to the bills due before the next one, set aside a share for savings and debts, and see what is safe to spend until the next payday. It takes a little more setup because you need each bill's due date, but it avoids the trap of spending the "monthly" money early and being short when the mortgage comes due.

Common mistakes to avoid

Planning with income you haven't received yet. Use only what you have or are certain to receive.
Forgetting irregular costs. Car repairs, gifts and annual fees aren't monthly, but they come. Add them as savings categories (sometimes called sinking funds) and put a little in each month.
Making too many categories. Fifteen to twenty is plenty. More makes logging a chore.
Giving up after one bad month. A budget that is over in a few places is still information. Adjust the plan and keep going.

Google Sheets limits to know about

A budget with a few hundred transactions a year is easy for Sheets. If you log thousands of rows with complex formulas, it may slow down. Sheets doesn't connect to your bank on its own, so you will enter transactions yourself, which is a feature if you want to stay aware of spending and a cost if you'd rather automate it. It also doesn't send alerts by email without scripts, which these templates intentionally avoid.

Skip the setup

If you would rather start with the structure built, the Monthly Budget Spreadsheet gives you the plan-against-actual view, Over and Watch flags and a whole-year view, with no bank logins. If your pay arrives on a schedule and bills are your main worry, the Paycheck Budget Planner shows which bills each paycheck covers and how much is safe to spend before payday. The Spending Tracker is built around logging and reviewing your spending, and the Subscription Tracker keeps your recurring subscriptions in one list. You can also browse all the Personal Finance templates.