Enter take-home income and expenses to see what’s left over, each category’s share of income, and your savings rate.
Monthly Budget Formula
The calculator converts your income to a monthly figure, totals your expenses, and shows what is left:
L = I - (E1 + E2 + ... + En)
Variables:
- L is the money left over each month (a negative result is a monthly deficit)
- I is your monthly take-home income. Biweekly pay is converted as pay x 26 / 12, weekly pay as pay x 52 / 12, and annual pay as pay / 12
- E1 through En are your monthly expenses by category: housing, utilities and bills, groceries and food, transportation, insurance and healthcare, debt payments, subscriptions and fun, and everything else
Select how you are paid, enter your take-home pay for that period, then fill in whichever expense categories apply. The calculator normalizes everything to a month, totals your spending, and reports the leftover amount, each category's share of income, and your implied savings rate. Categories left blank simply count as zero.
Typical Budget Shares of Take-Home Pay
This table shows common guideline ranges for each category as a share of monthly take-home income. Your own numbers will vary with city, household size, and season of life; the ranges are a sanity check, not a rulebook.
| Category | Guideline share | On $4,500/month |
|---|---|---|
| Housing | 25% - 35% | $1,125 - $1,575 |
| Utilities & bills | 5% - 10% | $225 - $450 |
| Groceries & food | 10% - 15% | $450 - $675 |
| Transportation | 10% - 15% | $450 - $675 |
| Insurance & healthcare | 5% - 10% | $225 - $450 |
| Debt payments | 0% - 10% | $0 - $450 |
| Subscriptions & fun | 5% - 10% | $225 - $450 |
| Savings (leftover) | 15% - 20%+ | $675 - $900+ |
Example Problems
Example 1: A monthly budget with a surplus.
Your take-home pay is $2,250 biweekly. Monthly income = 2,250 x 26 / 12 = $4,875. Your expenses are $1,500 housing, $300 utilities, $650 food, $400 transportation, $250 insurance, $200 debt, and $300 fun, totaling $3,600.
L = 4,875 - 3,600 = $1,275 left over each month, an implied savings rate of about 26%.
Example 2: Spotting a deficit.
Monthly income is $3,800 and expenses total $4,050. L = 3,800 - 4,050 = -$250, a monthly deficit. The category table shows housing at 42% of income - well above the 25-35% guideline - which is the first place to look for a fix.
Frequently Asked Questions
Should I budget with gross or take-home income?
Use take-home (net) income - the amount that actually lands in your account after taxes and payroll deductions. Budgeting with gross income overstates what you can spend by 20-30% for most households. If your 401(k) contribution comes out of your paycheck automatically, you can treat it as savings that already happened.
What should I do with the leftover amount?
Give it a job before the month starts: emergency fund contributions, extra debt payments, and investing are the usual priorities in that order. Money without an assignment tends to get absorbed by everyday spending, which is why zero-based budgeting assigns every dollar on purpose.
How much should I keep for irregular expenses?
Annual and surprise costs - car repairs, gifts, insurance premiums - are the most common budget breakers. A practical fix is a sinking fund: total your irregular costs for the year, divide by 12, and set that amount aside monthly so those bills never feel like emergencies.
