Budget calculator
Enter your monthly income and your main expenses to see how much is left and what share of your income you save.
Free to use, no account needed. What you type stays in your browser.
Left each month
$600.00
Total expenses
$2,400.00
Savings rate
20%
You have money left each month. Decide where it goes before the month starts, for example savings, a debt payment or an emergency fund.
- Housing (rent or mortgage)$1,000.00
- Bills and utilities$300.00
- Food and groceries$500.00
- Transport$200.00
- Other expenses$400.00
- Left each month$600.00
The 50/30/20 guide
A common rule of thumb for splitting the same income. It is a starting point, not a rule.
Needs (50%)
$1,500.00
Wants (30%)
$900.00
Savings (20%)
$600.00
How this is calculated
A budget compares what comes in with what goes out. These are the formulas used:
- Money left each month
- I − (E₁ + E₂ + … + E₅)
- Savings rate
- (I − E) ÷ I × 100
- 50/30/20 guide
- I × 50% · I × 30% · I × 20%
I is your monthly income and E is the total of your monthly expenses.
The 50/30/20 guide puts 50% of income towards needs, 30% towards wants and 20% towards savings and debt repayment. It is a common rule of thumb, and your own numbers may differ, especially where housing is expensive.
Each amount is rounded to 2 decimal places before it is added, so the figures shown always add up.
Worked example
With a monthly income of $3,000.00 and expenses of $2,400.00, $600.00 is left each month, a savings rate of 20%. The 50/30/20 guide would put $600.00 into savings for the same income.
Budget questions
How do I make a monthly budget?
Write down your income after tax, list your regular expenses, and subtract the total from the income. What is left is what you can save or spend. Then compare it with last month and adjust.
What is the 50/30/20 rule?
It splits income after tax into 50% for needs such as rent and food, 30% for wants such as eating out, and 20% for savings and debt repayment. It is a guide, not a rule.
What counts as a need and what counts as a want?
Needs are costs you cannot avoid, such as housing, basic food, utilities and transport to work. Wants are things you could do without, such as subscriptions, takeaways and holidays. Some items sit in between.
How much of my income should I save?
Many guides suggest about 20%, but the right amount depends on your income, debts and goals. If 20% is not possible yet, start with a smaller fixed amount and raise it later.
Is my information stored or sent anywhere?
No. The calculation runs in your browser. The numbers you enter are not sent to us or saved.
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Results are estimates for planning. They are not financial, tax or religious advice.