See the effect of a regular loan top-up
Making more than the scheduled repayment can reduce a principal-and-interest loan balance sooner, so less interest accrues in later months. This calculator compares the original monthly schedule with one that adds the same extra amount every month from the start of the model.
Before changing payments, check your loan contract. A fixed loan may limit extra repayments or apply a break cost, and an offset, redraw facility or fee structure may change the practical result. The estimate helps frame a question for your lender rather than confirming what your account permits.
How to read the results
Time saved is the difference between the baseline number of monthly payments and the accelerated schedule. New loan term is the accelerated schedule’s total number of payments, while Final payment is the smaller exact amount needed in its last month.
Interest saved compares total interest in both constant-rate schedules. It is a modelled reduction, not cash credited to an account. The chart follows the accelerated balance only, and does not show fees, redraws, changing rates or missed payments.
Worked example
The defaults model a $650,000 balance at 6.34% with 30 years remaining and an extra $250 each month. The normal repayment is calculated internally at $4,040.29; adding the top-up clears the balance in 306 months rather than 360.
The displayed time saved is 54 months and estimated interest saved is $142,281. The accelerated final payment is $3,684.47, assuming every monthly top-up is made and the rate does not change.
Assumptions and limitations
- The starting balance is repaid by level monthly principal-and-interest payments.
- The interest rate remains 6.34% in the default example for the whole modelled period.
- The extra repayment is added at every month-end from the first month.
- Fees, offset balances, redraws, payment holidays and lender repayment rounding are excluded.
- The model uses an exact reduced final payment rather than a full scheduled repayment in the final month.
Frequently asked questions
Will my lender automatically shorten the term?
Lender processes differ; some retain the term and recalculate repayments, so confirm how additional payments are treated.
Can I enter an annual lump sum?
This tool models a regular monthly top-up only; a lump sum at a different time can produce a different result.
Are extra repayments always available?
No. Loan conditions, especially fixed-rate conditions, can impose limits or costs.
This calculator and supporting information provide general estimates only. They do not take account of every product rule, tax consequence or personal circumstance and are not financial, tax, credit or legal advice.