how this is calculated.
no spin. no lead-gen. no “debt consolidation specialist” emailing you tomorrow. just the model and where the numbers come from.
the model
we run a monthly simulation against your HECS-HELP balance. each month: compulsory PAYG repayment comes out at your salary’s marginal rate, any voluntary monthly repayment is subtracted, and on 1 June the balance is grown by your inflation rate (the ATO calls this “indexation”). salary growth is applied each 1 July (start of the Australian financial year).
the payoff month is the first month your balance hits zero. if inflation grows your debt faster than you can pay it, you’ll see “never”. that’s not a bug. that’s the system working as designed, on you.
compulsory repayments (FY2025-26)
we use a marginal-rate model on your gross salary as a proxy for repayment income:
- nothing under $67,000
- 15% on the slice between $67,000 and $125,000
- 17% on the slice above $125,000
real ATO calculations apply a single percentage to total repayment income and include reportable fringe benefits, foreign income, net investment losses, and exempt foreign employment income. for binding numbers, see ATO — study and training loan repayment thresholds and rates.
the 1 June inflation bump (a.k.a. indexation)
once a year, on 1 June, your HECS balance gets grown by inflation. the ATO calls this “indexation”. in plain english: your debt goes up by roughly CPI, before you’ve made a dent in it. the rate is the lower of CPI growth and WGI growth (per the 2023 legislative change). recent: 4.7% (2023), 4.0% (2024). we apply it to your full balance — for V1 we don’t model the 11-month exemption that protects newly-incurred debt.
voluntary repayments
anything you pay above the compulsory amount comes off the balance the same month. this is deliberately the “simple” treatment — voluntary repayments made before 1 June reduce the balance that gets indexed, which is the whole strategy.
what this tool isn't
- not financial advice.it’s a public estimator. nothing here accounts for your full financial situation, debts, dependants, or risk profile.
- not an ATO statement.we don’t pull your real balance or repayment income. log in to myGov for the source of truth.
- not a forecast. inflation projects forward at the rate you set. real CPI and WGI vary. the chart is a baseline, not a prophecy.
- not a substitute for talking to a professional. for tax planning around voluntary repayments, talk to a registered tax agent.
if you spot a problem
thresholds change, rates change, edge cases exist. please flag anything that looks off so we can keep this honest.