Budget Calculator
A budget only works when you can see the whole picture at a glance. This calculator takes your monthly income and your expenses by category, then shows you the total, what is left over and the share of income you are spending, so you can spot a creeping category before it becomes a hole in the month.
How the budget is calculated
-
1
Enter your monthly income
Type in the money you receive each month after tax, so the figures match what you actually have to spend.
-
2
Add expenses by category
Give each expense a name (rent, groceries, transport, subscriptions) and an amount. Add or remove rows as needed.
-
3
Read the totals
The calculator sums the expenses, shows what is left after them and the share of income they represent. A negative remainder means the month is overspent.
Reading the results
| Figure | What it means |
|---|---|
| Total expenses | The sum of every category you entered |
| Remaining | Income minus total expenses; negative means spending exceeds income |
| Expense ratio | Total expenses as a share of income, so you can compare months at a glance |
Example: $5,000 net per month
- Rent or mortgage: $1,500
- Groceries: $400
- Transport: $300
- Utilities: $200
- Entertainment: $150
Total expenses are $2,550, leaving $2,450 of the $5,000, an expense ratio of 51 percent. Keep the same categories from month to month and the ratio becomes an early warning: when it climbs, something in the list is changing.
Common pitfalls
- Irregular income, use the average of your lowest three months, not the peak.
- Yearly expenses, divide by 12 and budget monthly (insurance renewal, car registration, holidays).
- Sinking funds, set aside 1/12 of big irregular costs each month so they don’t ambush you.
- Lifestyle creep, if income rises, keep the same expense categories and put the raise into savings until you recalibrate deliberately.
Frequently Asked Questions
A common rule of thumb keeps needs near 50 percent of after-tax income, wants near 30 percent and savings at 20 percent (the 50/30/20 guideline). Use the ratio this calculator shows to see how your own spending compares, and remember housing is usually the largest category.
The calculator works with any period as long as income and expenses cover the same one: weekly, monthly or yearly. Enter both sides for the same period and the totals stay meaningful.
The remainder turns negative and the expense ratio goes above 100 percent. That is the signal to trim the largest categories or add income; the point of the budget is to see that gap clearly.
The amounts you enter are sent to our server to compute the totals, and in the step-by-step view they are carried in the page link between steps. Nothing is stored, shared or kept after you leave the page.
Related Tools
BMI Calculator
Calculate body mass index from height and weight. Shows WHO category, healthy-weight range and limitations of BMI.
Social Security Calculator
Estimate a US Social Security retirement benefit from your PIA and claiming age. Compare monthly and annual amounts at 62, FRA 67 and 70.
Age Calculator
Calculate exact age in years, months and days from a birth date, plus total days, hours and the next birthday countdown.
One Rep Max Calculator
Estimate your one-rep max (1RM) from weight lifted and reps completed using Epley, Brzycki and Lander formulas.
Amp-Hour Calculator
Work out battery runtime and stored energy from amp-hours, voltage and load current. Get runtime in hours and minutes plus energy in watt-hours and kilowatt-hours.
Scientific Calculator
Evaluate supported real-number expressions with trig, logs, powers and parentheses locally in your browser.