Buy-to-let remortgage calculators
Four quick sums, no sign-up. What the rent will support, whether a new deal beats your current rate once the fee is in, how much equity you could release, and what it costs a month.
What will the rent support?
Lenders divide the rent by a cover ratio and a stress rate. This does that sum the way most of them do it, then caps the answer at 75% of the value.
Basic-rate and company borrowers are usually tested at 125% cover; higher-rate at 145%.
Five-year fixes are usually stressed at the pay rate. Shorter deals at the higher of pay rate + 2% or 5.5%.
- What the rent supports
- £0
- 75% of the value
- £0
- Tested at
- –
Some lenders use different ratios, "top-slice" with your personal income, or lend to 80%. A broker will know which.
Is it worth switching?
Your current rate against a new deal, over the life of the deal, with the arrangement fee counted. Interest-only, which is how most buy-to-lets are set up.
Buy-to-let variable rates are often 8% to 9%.
- Current monthly interest
- £0
- New monthly interest
- £0
- Fee (added to the loan or paid)
- £0
Ignores valuation and legal costs (often free on remortgages) and any early repayment charge on your current deal. Compare two new deals by putting one in each box.
How much equity could I release?
A remortgage up to the lender's maximum loan-to-value, minus what you owe now, capped by what the rent supports at 125% cover.
- Maximum new loan
- £0
- Your loan-to-value now
- –
- Interest on the new loan
- –
Assumes a 5-year fix stressed at the pay rate (minimum 5.5%). Lenders ask what the money is for; a deposit on another buy-to-let is the usual answer and is fine.
Monthly payment
Interest-only or repayment. Most buy-to-lets are interest-only; the capital is repaid when the property is sold or refinanced.
- If the rate were 1% higher
- £0
- Total paid over the term
- £0
- Of which interest
- £0
Illustration only. Fees not included.
A note on the numbers. Rental cover ratios, stress rates, loan-to-value limits and fees are typical of the market at the time of writing (2026) and differ from lender to lender. Tax rules are for individuals and companies resident in the UK and change with each Budget. This is general information, not advice: a broker will tell you what applies to your property, and an accountant what applies to your tax.
Your deal is ending. Let's get a broker on it.
Two minutes of questions about the property. We match you with a buy-to-let specialist who calls you back, usually within one working day. Free, no obligation.