CalcAussie knowledge centre
Australian guides that explain the decision, not only the calculation
12 plain-English guides covering Australian tax, super, borrowing, property, household costs and energy. Each guide identifies the assumptions to test, the limits of a calculator and the official material worth checking before acting.
Original explanatory work
Worked decision frameworks written for Australian users and linked to relevant calculators.
Primary-source review
Government and regulator sources are listed so readers can verify material rules and limits.
Visible maintenance
Site-wide quality review completed 30 September 2026. Updates are recorded in the public review log.
Australian income tax rates 2026–27
Current resident tax brackets, how marginal tax works and what changed from 1 July 2026.
Read guideAustralian tax-free threshold 2026–27
How the $18,200 threshold works, when to claim it and what changes when you have multiple jobs.
Read guideHECS/HELP repayment rates 2026–27
The current minimum repayment income, marginal repayment bands and what counts as repayment income.
Read guidePayday Super from 1 July 2026
How the 12% super guarantee works with qualifying earnings and the new payday timing rules.
Read guideHow Australian mortgage repayments work
Understand principal and interest repayments, loan terms, rate changes and the assumptions behind an Australian mortgage estimate.
Read guideMortgage offset account versus redraw
Compare how mortgage offset and redraw arrangements reduce interest, preserve access to cash and differ in fees, access and tax consequences.
Read guideHow to compare the total cost of a car loan
Compare Australian car loans using repayments, fees, comparison rates, balloon payments and total interest rather than the monthly figure alone.
Read guideUsing compound interest without unrealistic assumptions
Learn how contributions, compounding, fees, tax, inflation and changing returns affect Australian savings and investment projections.
Read guideSalary sacrifice into super: what to compare
Understand how salary-sacrifice contributions affect taxable income, take-home pay, contribution caps and long-term super projections.
Read guideGST calculations for Australian small business
Understand GST-inclusive and GST-exclusive prices, GST registration, tax invoices and why collected GST is not business income.
Read guideHow to run a fair rent-versus-buy comparison
Compare renting and buying using complete cash flows, opportunity cost, time horizon and editable growth assumptions.
Read guideHow to check an Australian electricity bill
Understand supply charges, usage tariffs, billing periods and appliance estimates before comparing electricity plans or checking a bill.
Read guideHow these guides are maintained
CalcAussie separates sourced rules from estimates and user-entered assumptions. A guide is revised when a material rule changes, a calculator method changes or a correction is confirmed. We do not invent an Australian average where costs vary by provider, state or household.