Budget Planner Calculator

How It Works

The 50/30/20 rule is a simple way to split your after-tax income into three buckets: about 50% for needs, 30% for wants, and 20% for savings and extra debt payments. Needs are the essentials you cannot go without — housing, food, transport and utilities. Wants are the things that make life nicer but are not essential, like entertainment and dining out. Savings is whatever is left after your expenses, which is the money available to save or put toward debt.

The formulas are straightforward: total expenses = housing + food + transport + utilities + entertainment + other; remaining balance = income − total expenses; savings rate = remaining balance ÷ income × 100. The 50/30/20 targets are worked out from your income: needs target = 50% of income, wants target = 30% of income, savings target = 20% of income. Your actual amounts are needs = housing + food + transport + utilities, wants = entertainment + other, and savings = your remaining balance.

Worked example: with a monthly after-tax income of $4,000, housing $1,400, food $500, transport $300, utilities $200, entertainment $200 and other expenses $200, your total expenses are $2,800 and your remaining balance is $1,200, giving a savings rate of 30%. The 50/30/20 targets are needs $2,000, wants $1,200 and savings $800. Your actual amounts are needs $2,400 (60% of income), wants $400 (10%) and savings $1,200 (30%) — so needs run 10 points over target, wants are well under, and savings are ahead of target.

How to Use This Calculator

Start by entering your monthly after-tax income — the amount that actually reaches your bank account, not your salary before tax. If your pay varies month to month, use an average of the last few months, or your lowest typical month if you want to be cautious.

Then fill in your spending by category. Each expense field is optional and an empty field counts as zero, so you only need to enter the categories that apply to you. Use your last month of bank or card statements to get realistic figures — most people underestimate what they spend on food and entertainment, so checking your statements usually gives a truer picture than guessing. Results update as you type, and the bar chart below the results compares your actual needs, wants and savings against the 50/30/20 targets.

Tips and Practical Advice

The needs bucket is usually the hardest to move, because housing alone often takes a large share of income. If your needs are well over 50%, look at the smaller items first — a cheaper phone or internet plan, or lower utility bills — before considering a bigger change like moving. Wants are the easiest place to find quick wins: cutting one or two subscriptions or eating out less often can free up a noticeable amount without changing how you live day to day.

Pay yourself first if you can. Instead of saving whatever happens to be left at the end of the month, move your savings out of your spending account on payday, so it is already set aside before the month's spending starts. If your remaining balance is negative, the calculator shows it honestly — treat that as the starting point, not a failure: cut wants first, then look for savings on the biggest need, and revisit the numbers each month until the balance turns positive.

Finally, review your budget once a month and adjust the numbers as your income or spending changes. A budget is a plan you keep updating, not a one-time exercise, and the habit of checking in matters more than getting every category exactly right. Set a monthly reminder on your phone so the review actually happens.

Frequently Asked Questions