MrBudgeting.com provides eight free budgeting calculators for the most common personal finance decisions. Use the Monthly Budget Planner to see whether your income covers your expenses, the 50/30/20 Calculator to divide your pay into needs, wants and savings, or the Debt Payoff Calculator to find out exactly when you'll be debt-free and how much interest you'll pay along the way. Every tool runs entirely in your browser. Upgrade to Pro for an ad-free experience, CSV exports and more.
Monthly Budget Planner
Mr B says: Start with your income at the top, then list every regular expense. The goal is simple — make sure the bottom line is positive before the month starts.
A monthly budget planner compares your take-home income against your planned expenses to show whether you end the month with money left over or in deficit. Enter your income, add every expense category, and the planner instantly calculates your remaining balance. A positive balance means you have surplus to direct toward savings or goals before spending begins.
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50/30/20 Budget Calculator
Mr B says: This rule is a starting point, not a straitjacket. If you live somewhere expensive, your 'needs' slice will naturally be bigger — that's fine. Just keep savings in the mix.
The 50/30/20 rule is a budgeting guideline that splits take-home pay into three categories: 50% for needs (rent, food, bills, transport), 30% for wants (dining out, entertainment, hobbies), and 20% for savings and debt repayment. Enter your monthly income below and the calculator shows your target dollar amount for each category. The percentages are a guide, not a rule — adjust them to match your real circumstances.
Savings Goal Calculator
Mr B says: Saving feels abstract until you attach a number and a date. Use the reverse mode to work backwards from your deadline — sometimes the monthly number is more motivating than the total.
A savings goal calculator works in two directions: enter a target amount and your monthly contribution to see how long it takes to reach your goal, or enter a target and a deadline to find out how much you need to save each month. Both calculations account for any savings you already have as a starting point.
Debt Payoff Calculator
Mr B says: Even a small increase to your monthly payment cuts the interest dramatically. Try bumping the payment by $50 and watch the payoff date move forward — it's satisfying.
A debt payoff calculator shows how long it will take to clear a debt at your current monthly payment, and the total interest you will pay over that period. Enter your balance, interest rate and monthly payment to see your payoff date and total cost. Increasing the monthly payment reduces both the payoff time and the total interest charged — even a small increase makes a significant difference on high-interest debt.
Bill Split Calculator
Mr B says: Include the tip before you divide. If you're splitting unequally, switch to custom mode and enter what each person had — much less awkward than negotiating at the table.
A bill split calculator divides a shared expense between a group of people. Split the total evenly across all participants, or switch to custom mode to enter individual amounts when people ordered differently. Factor in any service charge or tip before dividing to ensure the full cost is covered.
Emergency Fund Calculator
Mr B says: Three months is a good first target. Six months gives you real breathing room if something serious happens. Start saving toward three — you can always keep going.
An emergency fund is a cash reserve held in an accessible account to cover essential living expenses in the event of unexpected job loss, illness, or a major unplanned cost. Financial planners recommend having three to six months of essential expenses set aside. This calculator shows how many months of cover you currently have and how long it will take to reach a three or six month target at your current savings rate.
Pay Rise Calculator
Mr B says: The monthly difference is what matters most for budgeting — that's the number to plan around. Remember tax will take a slice of any increase.
A pay rise calculator converts a salary increase into the exact monthly and annual dollar difference so you can see precisely how much extra you will receive. Enter your current and new salary to get the figures instantly. Note: this calculator uses gross salaries — your actual take-home increase will be lower after income tax, and the precise amount depends on your tax rate and whether the increase pushes you into a higher bracket.
Net Worth Calculator
Mr B says: Don't panic if the number is negative — that's common early in life, especially with a mortgage or student debt. What matters is the direction of travel over time.
Net worth is calculated by subtracting everything you owe (liabilities) from everything you own (assets). Assets include savings, investments, property, vehicles, and superannuation or pension funds. Liabilities include mortgage balances, car loans, credit card debt, and personal loans. The resulting figure is your net worth — positive if assets exceed debts, negative if they do not. Nothing you enter is saved or sent anywhere.
Assets — what you own
Liabilities — what you owe
Key budgeting terms explained
- Budget
- A budget is a written plan that allocates your income to specific spending categories before the month begins. The purpose of a budget is to ensure spending is intentional, that savings targets are met, and that you end each month with more money than you started with.
- Net worth
- Net worth is the total value of everything you own (assets) minus everything you owe (liabilities). A positive net worth means your assets exceed your debts. A negative net worth means you owe more than you own. Net worth is the most complete single measure of financial health.
- Emergency fund
- An emergency fund is a dedicated cash reserve held in an accessible account, intended to cover essential living expenses in the event of job loss, illness, or a major unplanned cost. Financial planners typically recommend holding three to six months of essential expenses in an emergency fund.
- The 50/30/20 rule
- The 50/30/20 rule is a personal budgeting guideline that allocates 50% of after-tax income to needs, 30% to wants, and 20% to savings and debt repayment. It was popularised by US Senator Elizabeth Warren in her 2005 book All Your Worth. The rule provides a starting framework rather than a precise formula.
- Avalanche method (debt repayment)
- The avalanche method is a debt repayment strategy that directs extra payments toward the highest-interest debt first, while making minimum payments on all others. This approach minimises the total interest paid and is the mathematically optimal strategy for eliminating debt as quickly as possible.
- Snowball method (debt repayment)
- The snowball method is a debt repayment strategy that directs extra payments toward the smallest debt balance first. Once cleared, that payment amount rolls to the next smallest balance. The method prioritises psychological wins over mathematical efficiency and is effective for people who need visible progress to maintain motivation.
- Take-home pay (net income)
- Take-home pay, also called net income, is the amount received after income tax and other deductions have been removed from gross salary. All budgets should be built on take-home pay — not gross salary — to accurately reflect the money available to spend and save.
- Discretionary spending
- Discretionary spending refers to non-essential purchases that are chosen rather than required — such as dining out, entertainment, travel, subscriptions, and hobbies. It is the category most easily reduced when a budget is under pressure, making it the first place to look when expenses exceed income.
- Savings goal
- A savings goal is a specific, named financial target — such as a house deposit, holiday fund, or emergency buffer — with a defined dollar amount and, ideally, a target date. Named and specific goals are significantly more likely to be achieved than vague intentions to "save more".
Common questions
Budgeting basics, answered
Plain answers to the questions most people Google when they're trying to get their finances on track.