Learn the maths behind the calculators
Free guides explaining the formulas, concepts, and real-world applications behind every calculator on Calculy.
What is Compound Interest?
The formula, how it works, and why starting early beats investing more.
Read article →The Rule of 72 Explained
The fastest mental shortcut for estimating when your money doubles.
Read article →Australian Stamp Duty Guide
State-by-state rates, first home buyer concessions, and total buying costs.
Read article →Superannuation in Australia
How super works, contribution limits, preservation age, and retirement planning.
Read article →How to Calculate BMI
The formula, WHO categories, limitations, and better health measures.
Read article →What is TDEE?
Total daily energy expenditure — and how to use it for weight management.
Read article →How Much Mortgage Can I Afford?
The APRA buffer, HEM, DTI limits — and what banks actually assess.
Read article →What is Inflation?
How inflation is measured, what causes it, and how it erodes purchasing power.
Read article →How Banks Assess Borrowing Power
The exact 6-step process Australian lenders use to calculate your borrowing capacity.
Read article →Rent vs Buy in Australia
The true costs compared, break-even timelines, and which factors tip the decision.
Read article →Debt Snowball vs Avalanche
Which debt repayment strategy saves more money — with worked examples.
Read article →What is LMI in Australia?
Why LMI protects the lender (not you), what it costs, and how to avoid it.
Read article →How to Save a House Deposit
FHSS, FHBG, realistic timelines, and strategies to accelerate your deposit.
Read article →ETF Investing in Australia
How ETFs work, popular ASX options, dollar-cost averaging, and compound returns.
Read article →What is Negative Gearing?
How negative gearing works, the tax benefits, and whether the strategy makes financial sense.
Read article →First Home Buyer Grants & Schemes 2025
FHBG, FHSS, FHOG, and stamp duty concessions — every federal and state scheme in one place.
Read article →How to Read a Payslip in Australia
Every line explained — gross pay, PAYG tax, Medicare levy, HECS, super, and net pay.
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