How to build a monthly budget
A monthly budget is a plan for every unit of money you expect to receive in a month and where it will go. It does not need to be complicated. What it needs is to be written down before the month starts and compared with reality after it ends. This budget planner does both: you fill in the planned column first and the actual column as the month goes on.
- List your income. Use what actually lands in your account after tax, not your gross salary. Add each source on its own line: salary, a second job, benefits, side income.
- Start with fixed costs. Rent or mortgage, insurance, minimum debt payments, phone and internet. These are the lines you cannot easily change this month.
- Add variable spending. Groceries, fuel, eating out, clothes, fun money. Open last month's bank statement and use real numbers instead of guesses.
- Give savings its own lines. Treat savings and extra debt payments as planned outflows, not as whatever happens to be left at the end of the month.
- Check what is left. If the left-to-budget number is negative, trim the variable lines first. If it is positive, decide where that money goes.
The starter templates give you a ready structure for a single renter, a family, a student or a freelancer. The amounts in them are examples only, so replace every number with your own. If you prefer to start from scratch, use the Blank template: it keeps the categories and common line names with no amounts.
Zero-based budget vs the 50/30/20 rule
A zero-based budget means income minus all planned outflows equals zero. That does not mean spending everything: savings, an emergency fund and extra debt payments count as planned outflows. Every dollar, euro or pound gets a job before the month starts. The left-to-budget figure in the summary panel is your zero-based check. When it reaches exactly zero, the planner tells you every unit of income has a job.
The 50/30/20 rule is a quicker method: about 50% of after-tax income for needs, 30% for wants and 20% for savings and debt repayment. It is a good way to check the overall shape of a budget, but it does not tell you how much to spend on groceries this month. Many people use both: 50/30/20 to sanity-check the split, and a zero-based monthly budget template like this one for the detail.
Review planned vs actual every month
A plan is only a guess until you compare it with what happened. At the end of the month, or once a week for busy categories like food, fill in the actual column from your bank and card statements. The difference column shows how much is left or how much you went over on each line, and every category that went over its plan is flagged in the checks list.
For each overspent category, ask one question: was the plan unrealistic, was it a one-off, or is it a habit? Raise the plan if it was unrealistic, leave it if it was a one-off, and make a change if it is a habit. Then press Copy plan to next month. It carries the planned amounts forward and clears the actuals, so next month starts from a plan that has already been tested once.
Budgeting with irregular income
If you freelance, earn commission or work seasonally, an average month is a risky number to plan on. Plan on a lean month instead, such as the lowest income you had in the last six to twelve months. Anything you earn above that goes to an income buffer and to tax.
- Income buffer. Aim for about one month of expenses in a separate account. In good months it fills up; in slow months you pay yourself from it, so your personal budget stays steady.
- Tax set-aside. If no tax is taken from your payments, move a share of every payment to a separate account. Check the right share with your local rules or an accountant.
The Freelancer template already includes both lines in the Savings category.
Sinking funds for bills that are not monthly
Annual insurance, car repairs, holidays, gifts and yearly subscriptions break budgets because they do not arrive every month. A sinking fund fixes that: divide the yearly cost by 12 and budget that amount every month as a line in Savings. A bill of 600 a year becomes 50 a month. When the bill arrives, it is paid from the fund and the month stays on plan.
Take it further
Download the CSV to keep a yearly record in a spreadsheet, and use the Excel formula generator to build SUMIF or monthly roll-up formulas. If you plan in Notion, the Notion planner template page helps you set up a planning workspace, and life admin AI covers bills, paperwork and renewals. For more free tools, see the free AI generators and tools hub.
FAQ
Is this budget planner free?
Yes. There is no sign-up and no limit. The planner runs in your browser and saves the months you edit only in this browser, so your numbers are not sent to our servers. You can clear one month or delete all saved months at any time.
What is a zero-based budget?
A zero-based budget gives every unit of income a job before the month starts, so income minus all planned outflows equals zero. Savings and extra debt payments count as outflows, so a zero-based budget is not about spending everything.
Should I use a zero-based budget or the 50/30/20 rule?
The 50/30/20 rule is a quick check on the overall split between needs, wants and savings. A zero-based budget plans each line in detail. Many people use 50/30/20 to set the shape and a zero-based monthly budget to plan the actual amounts.
How do I budget with irregular income?
Plan on a lean month, such as your lowest income in the last six to twelve months, not an average month. Put anything you earn above the plan into an income buffer and a tax set-aside. The Freelancer template includes both lines.
Can I keep several months and reuse my plan?
Yes. Use the month selector to switch months. Copy plan to next month copies the planned amounts and clears the actual column. Each edited month is kept in this browser, and you can export any month as CSV or print it as a sheet.