Budget Calculator

Managing a monthly budget is one of the most effective ways to gain control of your finances, yet many people struggle to see where their money actually goes. This Budget Calculator simplifies the process by letting you enter all income sources and expense categories in one place, then instantly calculating your monthly surplus or deficit, savings rate, and how your spending compares to the widely used 50/30/20 rule. It supports 22 currencies, so you can use it regardless of where you live. Whether you are building your first budget, recovering from a deficit, or optimizing a healthy surplus, this tool provides clear, actionable insights. All calculations run in your browser, so your financial data stays private.

How to Use the Budget Calculator

1. Select your currency from the dropdown menu.

2. Enter your primary income (after tax) and any secondary income.

3. Add passive income and other income if applicable.

4. Enter monthly housing costs (rent or mortgage).

5. Input utilities (electric, water, internet, phone).

6. Add food and groceries spending.

7. Enter transportation costs (fuel, transit, parking).

8. Input healthcare and insurance premiums.

9. Add entertainment and dining out expenses.

10. Enter education or childcare costs if applicable.

11. Input debt payments (loans, credit cards).

12. Add savings and investments contributions.

13. Enter any other miscellaneous expenses.

14. Click Calculate to view your budget summary.

15. Review the 50/30/20 rule analysis and expense category breakdown.

How the Budget Calculator Formula Works

The Budget Calculator uses simple arithmetic combined with the 50/30/20 budgeting framework.

Total Income:

Total Income = Primary + Secondary + Passive + Other

Total Expenses:
Total Expenses = Housing + Utilities + Food + Transport + Health + Entertainment + Education + Debt + Savings + Other

Monthly Surplus/Deficit:
Surplus = Total Income − Total Expenses

Savings Rate:
Savings Rate = (Savings + max(Surplus, 0)) ÷ Total Income × 100

50/30/20 Rule:

• Needs (50%): Housing, utilities, food, transport, healthcare, education, minimum debt payments

• Wants (30%): Entertainment, dining out, hobbies, subscriptions

• Savings (20%): Savings, investments, emergency fund, retirement

Classification:

• Healthy Surplus: Surplus > 0 and savings rate ≥ 20%

• Surplus: Surplus > 0 but savings rate < 20%

• Balanced: Surplus = 0

• Deficit: Surplus < 0 and deficit < 20% of income

• Critical Deficit: Deficit ≥ 20% of income

Worked Example

Consider a household with the following monthly finances:

Income:

• Primary income: $4,500

• Secondary income: $500

• Passive income: $0

• Other income: $0

• Total Income: $5,000

Expenses:

• Housing: $1,400

• Utilities: $250

• Food: $500

• Transport: $350

• Healthcare: $300

• Entertainment: $250

• Education: $0

• Debt: $300

• Savings: $400

• Other: $150

• Total Expenses: $3,900

Step 1 – Calculate surplus:
Surplus = $5,000 − $3,900 = $1,100

Step 2 – Calculate savings rate:
Effective savings = $400 + $1,100 = $1,500
Savings rate = ($1,500 ÷ $5,000) × 100 = 30%

Step 3 – Classification: Healthy Surplus (savings rate ≥ 20%)

Step 4 – 50/30/20 analysis:

• Needs = $3,100 (62% of income) → Over the 50% target

• Wants = $250 (5% of income) → Well within the 30% target

• Savings = $400 (8% of income) → Below the 20% target, but the surplus effectively raises it

Interpretation: You have a healthy monthly surplus and a strong effective savings rate. However, needs are above the recommended 50%, driven primarily by housing costs. Consider reviewing housing or transport expenses to bring needs closer to target, and redirect part of the surplus into automated savings or investments.