Simulate any loan based on daily interest accrual without monthly approximations. Model how an offset account, extra repayments, or lump-sum deposits change your balance and total interest paid over the life of the loan.

Loan details
Load a preset or save your session ▼
$
% p.a.
I know the:
Length of the loan
Repayment amount
yrs
mo
Pay at start or end of each period
📊
Enter loan details to begin
Load a preset from the loan details panel, or fill in the form and click Calculate.
Balance over time
Offset and extra repayments
? What is offset vs redraw vs extra payments?
Extra repayments
Applied directly to principal, permanently reducing your loan balance. Your required repayment stays the same, but a greater share goes to principal each period.
Offset account
Your offset balance reduces the interest charged each day, but the money stays in your account and is never applied to principal. You can spend it freely at any time.
Redraw facility
Model redraw the same way as extra repayments. Redraw just means you may be able to withdraw those extra funds later — the interest savings are identical either way.
$
$
One-time events
Offset deposit
Extra repayment
Offset behaviour settings
What do these do?
Repay instantly when offset ≥ balance
Closes the loan the moment your offset balance reaches the remaining principal. Useful for finding the earliest possible full-repayment date. The "When" field defers this to a specific year and month.
Stop adding to offset when offset covers balance
Once offset equals or exceeds the loan balance, new periodic offset additions stop. The loan accrues no further interest but is not formally closed — your savings remain accessible.
Stop repayments when offset covers balance
Once offset covers the balance, regular cash repayments cease. Each period the loan is paid down using your offset savings directly — both offset and principal fall together. Forces redirect on at the repayment amount.
Redirect offset to repayments when offset covers balance
After each repayment period, if offset exceeds principal, both are reduced by the redirect amount. Payment amount mode drains a fixed sum each period. Target offset balance mode drains any surplus above a floor you set — offset never falls below principal.
Repay instantly when offset ≥ balance
Stop adding to offset when offset covers balance
Stop repayments when offset covers balance
Redirect offset to repayments when offset covers balance
Mode:
$

Year 0, month 0 fires before the loan begins. Use year/month to set when the deposit occurs.

Timing (yr / mo) Amount ($)
Save session

Your current loan details, offset settings, repayment configuration, and all one-time events will be saved to this browser's local storage.

This will overwrite any previously saved session. The next time you open this page, your session will be restored automatically.