What this interest-only mortgage calculator does
This calculator shows payments on an interest-only mortgage. You enter the loan, the rate and the term. The tool then shows your monthly payment. During the interest-only phase you pay only interest. It also shows the balance that remains. You can compare it with a repayment loan. The result helps you weigh the two clearly.
How an interest-only mortgage works
An interest-only mortgage delays repaying the loan. Each month you pay only the interest due. The balance you owe stays the same. This makes the monthly payment lower. The lower payment lasts for a set period. After that, you must repay the principal. The plan needs careful thought from the start.
The interest-only period
The interest-only phase lasts a fixed time. It often runs for several years. During this phase your payment is smaller. None of it reduces the amount you owe. When the phase ends, payments rise. You then repay the principal as well. Knowing this date is very important.
Lower payments, unchanged balance
The appeal is a lower monthly cost. You free up cash during the period. But the loan balance does not fall. You still owe the full amount later. Interest is charged on that full balance. Over time this can cost more in total. The saving today has a price tomorrow.
Interest-only versus repayment
A repayment mortgage pays interest and principal. Its payment is higher each month. But the balance falls steadily over time. An interest-only loan keeps the balance fixed. It costs less now and more later. The right choice depends on your plan. Compare both before you commit.
Who an interest-only mortgage suits
Some borrowers use it on purpose. Landlords often prefer the lower payment. People with uneven income may value flexibility. Others plan to repay with a future lump sum. It can suit a clear, funded plan. It is risky without one. Be honest about how you will repay.
The risks to weigh
The main risk is the unpaid balance. You must repay it in full one day. Your repayment plan might fall short. Property values can also fall. Rising rates raise your interest cost. Without a plan, you could be forced to sell. Weigh these risks before you choose.
How to use it
Enter the loan amount you need. Add the interest rate and the term. Read the interest-only monthly payment. Then compare it with a repayment figure. See how much the balance remains. Try different rates to test the risk. Use it to judge if the plan fits.
Planning to repay the principal
An interest-only loan needs a repayment plan. Some save into investments alongside it. Others plan to sell the property later. Some switch to a repayment loan in time. Whatever the plan, it must be realistic. Review it as your situation changes. A funded plan turns risk into a choice.
Common mistakes to avoid
A common mistake is having no repayment plan. Another is ignoring the balance entirely. Some assume prices will always rise. That assumption can fail badly. Others forget that rates can climb. The lower payment can lull you into comfort. Plan for the full debt from day one.
A final tip
Treat an interest-only mortgage with care. Use it only with a clear repayment plan. Know the date the cheaper phase ends. Set money aside for the balance from the start. Compare the total cost with a repayment loan. Review your plan as life changes. Eyes open, it can be a useful tool.