Split Loan Calculator
Split Loan Calculator: Fixed and Variable
Enter your loan, how much to fix, and the two rates you’re comparing. See the repayment on each part, the total, and how a rise in the variable rate would change it.
Your loan
Enter the loan, the share to fix and both rates. The rise is optional.
Enter the loan, share to fix, both rates and the term to see your repayments.
Results are estimates only, based on the figures you enter. They assume principal and interest repayments, monthly, with each rate unchanged for the whole term, except that any rise you test applies from the start. They aren’t a quote, an approval or financial advice, and they don’t consider your objectives, financial situation or needs. Fees and charges aren’t included.
How it works
How a split loan is worked out.
Two loans in one
A split loan divides your borrowing into a fixed part and a variable part. Each part has its own rate and its own repayment. Your total repayment is the two added together.
The formula
Each part uses the standard principal and interest formula: the monthly rate is the yearly rate ÷ 12, the number of payments is the term in years × 12, and the repayment is amount × monthly rate ÷ (1 − (1 + monthly rate)^−payments).
Testing a rate rise
During the fixed period, the fixed part’s repayment doesn’t change. A rise in the variable rate only changes the variable part. The calculator shows how much more you’d pay a month on your split against a loan that was all variable.
What it leaves out
Fixed rates last for a set period, then usually revert to a variable rate. Fixed loans may have break costs if you repay early or switch, and limits on extra repayments. Fees aren’t included. Read split home loans explained for the trade-offs.
Questions
Common questions, straight answers.
How does a split loan calculator work?
It treats your loan as two loans: the fixed part and the variable part. It works out the principal and interest repayment on each over the term you enter, then adds them together.
What percentage should I fix?
There’s no set answer. Fixing more gives more certainty about repayments for the fixed period; keeping more variable keeps more flexibility, such as extra repayments or an offset. It depends on your budget and plans. Lenders also set their own limits on each split.
Does the fixed rate stay for the whole term?
No. A fixed rate lasts for the fixed period, often one to five years. After that the fixed part usually reverts to a variable rate unless you fix again. This calculator uses your fixed rate for the whole term to keep it simple, so treat later years as a rough guide.
Can I have an offset on a split loan?
Often on the variable part. Some lenders allow an offset on fixed loans too, with conditions. Ask us which lenders on our panel do.
Are rates in the calculator real rates?
No. You enter your own rates. To see advertised rates, each with its comparison rate, go to our home loan rates by lender page.
Weighing fixed and variable?
No obligation. No pressure. Just honest answers.
We don’t charge you for our service. Lenders pay us a commission if you go ahead with a loan.