RIO Calculator Results Explained: What They Show and What They Leave Out
Written and reviewed by the Later Life editorial teamUpdated 5 min read
RIO calculator results show the estimated monthly interest on a loan, and how much of your income it would take. They cannot tell you whether a lender would accept you, what fees apply, how rates might change or whether a retirement interest-only (RIO) mortgage suits your wider plans. Read the result as a budgeting guide, not a decision.
If you have not run your own figures yet, start with the tool, then come back here to make sense of the result.
Try the RIO affordability calculator
This article is general information, not financial advice. For how RIO mortgages work overall, see our guide to retirement interest-only mortgages.
What your RIO calculator results are made of
Our calculator produces two numbers.
- Monthly interest: the loan amount multiplied by the interest rate, divided by twelve. With a RIO mortgage you pay only the interest, so this is the regular payment and the loan itself does not go down.
- Borrowing ratio: the monthly interest plus any existing debt or mortgage payments, as a share of your household income after tax.
The capital is usually repaid when the home is sold after the last borrower dies or moves permanently into long-term care. So a lower monthly figure than a repayment mortgage does not mean a smaller debt; the full amount borrowed stays outstanding.
Reading the affordability bands
The result falls into one of three broad bands: under 30% of your income, 30% to 45%, and over 45%. These bands are a simple guide used by our tool, not any lender's criteria.
- Lower band: the interest takes a modest share of income. That is encouraging for budgeting, but it is not an approval.
- Middle band: the payment is manageable on paper, but there may be less room for rate rises, repairs or a drop in income.
- Upper band: the payment takes a large share of income. It may be worth looking at a smaller loan or other routes before going further.
Lenders set their own affordability tests, which can differ from these bands. Our article on how a RIO affordability calculation works explains what lenders typically look at.
Stress-testing the result
The calculator starts with an illustrative rate of 6.5%, which is not a current market rate, so change it if you have a quote. Then run it again in two ways.
A higher rate
Suppose, as an example, a homeowner considers borrowing £80,000 at 6% a year. The monthly interest would be around £400. At 7%, it would be around £467, an extra £800 over a year. Testing one or two percentage points higher shows whether your budget could absorb a rise when a fixed period ends.
One income instead of two
If the mortgage would be in joint names, re-run it using only the income one of you would have alone. Pensions often fall when a partner dies, and the survivor usually has to keep paying. If the result moves into a higher band, that is worth discussing before you apply.
What a RIO calculator can't tell you
- Whether you are eligible. Lenders look at age, credit history, the property and how much you want to borrow against its value. Our guide to RIO eligibility and affordability covers these checks.
- The full cost. Arrangement, valuation, legal and advice fees, and any early repayment charges, are not included.
- How secure your income is. The tool takes the income you enter at face value. Income that could stop or fall may be treated more cautiously by a lender.
- Your plans. It cannot weigh a future move, a wish to repay the loan early, or the effect on what you leave to family.
- The alternatives. A lifetime mortgage, a form of equity release, needs no monthly payment but the debt grows; downsizing avoids new debt but means moving.
Taking your RIO calculator results to an adviser
Note the loan amount, the rates you tested, each person's income after tax, your outgoings and what the money is for. An adviser can then check your figures against real lender criteria, fees and product terms. RIO mortgages are regulated by the Financial Conduct Authority, and you can check that an adviser is authorised on the FCA register. MoneyHelper's guide to RIO mortgages is a free, impartial place to read more.
Frequently asked questions
What does the monthly figure in a RIO calculator result represent?
It is the estimated interest for one month on the loan amount and rate you entered: the loan multiplied by the annual rate, divided by twelve. With a retirement interest-only (RIO) mortgage that interest is the regular payment, so the loan itself does not go down. The figure leaves out fees, and it will change if the rate changes after any fixed period.
If my RIO calculator result is in the lowest band, will a lender accept me?
Not necessarily. The bands on our calculator are a simple guide used by the tool, not any lender's criteria. A lender will also look at your age, credit history, the property, how much you want to borrow against its value and your wider spending. A comfortable result is a useful sign for budgeting, not an approval.
Why run a RIO calculator again with only one income?
A RIO mortgage usually continues until the last borrower dies or moves into long-term care, so the survivor may have to keep paying alone. Pensions often fall when a partner dies. Re-running the calculator with the income one of you would have on your own shows how much room there would be, which lenders also tend to consider.
What interest rate should I use to stress-test my RIO calculator result?
Start with a rate from a real quote or an adviser if you have one. Then try one or two percentage points higher to see how the payment and your affordability band would change. This is an illustration only, not a forecast, but it shows whether your budget has room if rates rise when a fixed period ends.
What should I take to an adviser after using a RIO calculator?
Bring the loan amount and rate you tested, your income after tax for each person, your regular outgoings and debts, and a note of what the money is for. Mention any plans to move, repay early or help family. An FCA-regulated adviser can then check the figures against real lender criteria, fees and product terms.
