1. What is the Mortgage Interest Calculator?

This calculator helps you determine the total interest you'll pay over the life of your mortgage, following Martin Lewis's advice on understanding mortgage costs.

2. How Does the Calculator Work?

The calculator uses the mortgage interest formula:

Where:

• \( PMT \) — Monthly mortgage payment (GBP)
• \( n \) — Total number of payments (months)
• \( PV \) — Principal loan amount (GBP)

Explanation: The formula calculates the total amount paid over the loan term and subtracts the principal to determine just the interest portion.

3. Importance of Interest Calculation

Details: Understanding your total interest helps compare mortgage offers, plan long-term finances, and decide whether overpayments could save you money.

4. Using the Calculator

Tips: Enter your monthly payment amount in GBP, the loan term in months, and the principal amount. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why calculate total interest?
A: It shows the true cost of borrowing and helps compare different mortgage products beyond just the interest rate.

Q2: How accurate is this calculation?
A: This gives a good estimate assuming fixed payments. For variable rate mortgages, actual interest may differ.

Q3: Can I reduce my total interest?
A: Yes, by making overpayments, shortening the term, or securing a lower interest rate.

Q4: Does this include other fees?
A: No, this calculates only the interest portion of your payments. Additional fees would increase total cost.

Q5: What's a good interest amount?
A: Lower is better, but context matters. Compare as a percentage of principal and relative to property value growth.