Budget Calculator – Plan Monthly Income and Expenses
Plan a monthly budget and see your surplus or shortfall.
About the Budget Calculator
What is the Budget Calculator?
A budget calculator sums your monthly income and expenses to reveal your surplus or shortfall, with a category breakdown.
Why use this calculator?
You cannot manage what you do not measure. A simple income-versus-expense budget is the foundation of every savings and debt plan.
How to use it
- Enter your monthly after-tax income.
- Enter your spending for each category.
- Adjust the numbers so your surplus is positive.
- Use the category percentages to spot overspenders.
Formula
Surplus = income − total expenses.
A common starting split is 50% needs, 30% wants, 20% savings and debt, but adapt it to your life.
Frequently Asked Questions
What is the 50/30/20 rule?
Spend about 50% of after-tax income on needs, 30% on wants, and save or use 20% for savings and debt payoff.
Does this include irregular expenses?
The form uses average monthly values. Add annual bills divided by 12 so you are not surprised by insurance or subscriptions.
How much should I save each month?
A common guideline is 20% of income, but the right number depends on your goals. Work backwards from your target amount and time frame.
What is an emergency fund and how big should it be?
It is cash set aside for unexpected expenses. Most planners suggest three to six months of essential living costs.
Where should I keep short-term savings?
High-yield savings accounts and money-market funds are typical because they are liquid and low risk, even if returns are modest.
What is the rule of 72?
Divide 72 by your annual interest rate to estimate how many years it takes to double your money. At 6%, that is about 12 years.
Is this calculator free to use?
Yes. Every calculator on this site is completely free, with no hidden fees, no subscriptions and no limits on how many times you can use it.
How accurate are the results?
We use standard, widely accepted formulas and calculate in your browser using double-precision arithmetic. Results are rounded for readability, so treat them as reliable estimates rather than a guarantee. Real-world factors can vary the true figure.
Can I add this calculator to my own website?
Yes. Open this calculator page and use the "Add to your website" box in the sidebar to copy a ready-made iframe snippet, then paste it into any HTML page.
Does it work on a phone or tablet?
Yes. The layout is fully responsive, so it works on desktops, laptops, tablets and mobile phones, and every input adapts to touch screens.