Total monthly income against a customizable list of expenses to calculate your surplus and savings rate.
How to Use the Budget Calculator
Enter monthly income at the top, then list expenses one row at a time — a category name and an amount — using the add and remove buttons to match however many lines your actual budget needs. The default seven rows are just a starting skeleton; rename, delete, or add to them freely.
The 50/30/20 rule is the reference point this tool measures against: roughly 50% of income to needs, 30% to wants, and 20% to savings or debt paydown. It comes from Senator Elizabeth Warren's book 'All Your Worth,' and it's a popular rule of thumb, not a law of personal finance handed down from anywhere official — plenty of reasonable budgets land well outside it, especially in high cost-of-living areas.
Total Expenses = sum of every row
Savings Rate = (Monthly Income − Total Expenses) ÷ Monthly Income × 100This calculator doesn't sort your rows into needs and wants on its own — "Housing" is obviously a need and "Other" could be either, and there's no reliable way to guess that from a category name alone. What it does measure is the bottom line: whatever's left after every expense is subtracted, compared against the rule's 20% savings target.
Run the seven default categories against a $5,000 income and the total comes to $3,250 in expenses, a $1,750 surplus, and a 35% savings rate — well clear of the $1,000 (20%) benchmark. Change any single row and both the surplus and the rate shift immediately, which makes this a reasonable place to test "what if I cut the debt payment in half" scenarios before committing to one.