Mortgage Calculators
Interest-Only Mortgage Calculator
Compare the payment during an interest-only period with the repayment that follows once capital repayment begins.
Interest-only payment
$1,750.00
- Payment afterwards
- $2,255.05
- Payment increase
- $505.05
- Total interest over the term
- $431,516
How this calculator works
Interest-only payment = P × r; later payment amortises P over the remaining term
- P
- the loan amount, unchanged during the interest-only period
- r
- the monthly interest rate
Important considerations
- The balance does not fall at all during the interest-only period.
- The payment jump at the end is the main risk — model it before committing.
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Learn more
Fixed vs. Variable Mortgage Rates: A Side-by-Side Comparison
How rate structure affects monthly payments, total interest, and the risk you carry over a full loan term.
When Refinancing a Mortgage Changes Your Total Cost
How break fees, remaining term, and the new rate combine to decide whether refinancing saves anything.
Home Loan Deposits and Loan-to-Value Bands, Explained
What a deposit changes about pricing, and why lenders group applications into LTV bands.
Terms used here
Frequently asked questions
Why is interest-only cheaper at first?
Because you are not repaying any capital, so the balance and the interest on it stay the same.
Disclaimer
Legamoney calculators are educational tools. Results are estimates based on the figures you enter and do not constitute financial, tax or legal advice.
Last reviewed 2026-08-01