ProReckoner's free finance calculators help Australians make better money decisions. Calculate your home loan repayments, estimate stamp duty for any state, work out your income tax for 2024โ25, project your superannuation balance at retirement, and run business profitability and break-even analysis. All tools use current Australian rates and are updated annually.
Home Loans
2 toolsHome Loan Repayment Calculator
Monthly repayments, total interest and total cost for any mortgage. The most important financial calculation most people ever make.
M = P ร [r(1+r)โฟ] รท [(1+r)โฟโ1]
Where P = principal, r = monthly rate, n = total payments.Key insight: On a $500K loan at 6.5% for 30 years, you pay approximately $640K in interest alone โ more than the loan itself.
Stamp Duty Estimator
Estimated stamp duty for property purchases across all Australian states and territories. Includes first home buyer concessions.
Tax & Super
2 toolsIncome Tax Calculator
Australian PAYG income tax estimate for 2024โ25. Shows tax payable, Medicare levy, effective tax rate and take-home pay.
$0โ$18,200: nil ยท $18,201โ$45,000: 19ยข per $1 over $18,200
$45,001โ$120,000: $5,092 + 32.5ยข ยท $120,001โ$180,000: $29,467 + 37ยข
$180,001+: $51,667 + 45ยข ยท Plus 2% Medicare levy
Superannuation Calculator
Projected superannuation balance at retirement. Shows employer contributions, growth and the power of extra contributions.
Annual contributions = Salary ร 11.5% + Extra
Compound growth means small extra contributions early have outsized impact at retirement.
Savings & Investing
2 toolsSavings Goal Calculator
How long to reach a savings target, or how much to save per month to hit your goal by a deadline.
Compound Interest Calculator
How much an investment grows over time with compound interest. Shows the dramatic effect of time and reinvestment.
A = P ร (1 + r/n)^(nt)
Einstein reportedly called compound interest the "eighth wonder of the world." A $10,000 investment at 8% for 30 years grows to over $100,000 โ without adding another cent.
Budget
2 toolsLoan Comparison Calculator
Compare two loans side by side โ monthly repayment, total interest and total cost. Find out which deal is really better.
Monthly Budget Tracker
Income vs expenses snapshot. See your surplus or shortfall and where your money is actually going.
Business & Investment
5 toolsExtra Mortgage Repayment
How much time and interest you save by paying extra each month. The most powerful personal finance calculation most people never do.
Interest saved = Total interest (original) โ Total interest (with extras)
On a $450K loan at 6.5%, paying an extra $500/month saves approximately $130,000 in interest and pays off the loan 8 years early.
Break-Even Calculator
How many units you need to sell to cover your costs. Essential for every sole trader, small business and product launch.
Contribution margin = Selling price โ Variable cost per unit
Break-even (units) = Fixed costs รท Contribution margin
Example (Finance Formulas Cheatsheet):Fixed costs $5,000 ยท Price $80 ยท Variable cost $30
Contribution = $50 ยท Break-even = 5,000 รท 50 = 100 units/month
Profit Margin Calculator
Gross, operating and net profit margins. The three numbers every business owner should know cold.
Gross margin = (Revenue โ COGS) รท Revenue ร 100
Operating margin = Operating income รท Revenue ร 100
Net margin = Net income รท Revenue ร 100
Healthy benchmarks: Gross >40% ยท Operating >15% ยท Net >10%These vary significantly by industry โ compare against your sector averages.
NPV & Payback Period
Is this investment worth it? Net present value and simple payback period from upfront cost and annual cash inflows.
Payback period = Initial investment รท Annual cash inflow
NPV = ฮฃ [Cash flow รท (1 + r)โฟ] โ Initial investment
Decision rule: NPV > 0 means the investment creates value. NPV < 0 means you'd be better off investing elsewhere at your discount rate.
Depreciation Calculator
Annual depreciation for business assets using straight-line or declining balance methods. Essential for tax and accounting.
Straight-line: (Cost โ Salvage) รท Useful life
Declining balance: Book value ร Depreciation rate%
SYD: Remaining life รท Sum of years digits ร (Cost โ Salvage)
Straight-line gives equal deductions each year. Declining balance front-loads deductions โ better for tax in early years. Always confirm with your accountant or the ATO.