Remortgage Calculator

What is this?

A Remortgage Calculator compares the mortgage deal you are on with the one you are considering moving to. It works out both monthly payments, the difference between them, the saving across the length of the new deal, and the interest each rate costs over the remaining term.

How to Use the Remortgage Calculator

A remortgage calculator compares the mortgage deal you are on with the one you are thinking of moving to. It works out both monthly payments, the difference between them, and - the part that actually decides it - whether the arrangement fees are worth paying.

It shows what you pay now, what you would pay on the new rate, the saving across the deal period, and the interest each rate costs over the whole remaining term. Fees and early repayment charges sit outside the calculation, so weigh those up separately before deciding.

1. Choose the Repayment Type

Repayment mortgages clear the capital over the term. Interest-only mortgages pay only the interest, with the balance repaid at the end. The two produce very different monthly figures on the same balance.

2. Enter Your Balance and Term

Enter what you still owe and how long is left to run, in years and months. Both come from your most recent mortgage statement.

3. Enter Both Interest Rates

Enter the rate you pay now - often your lender's standard variable rate if a fixed deal has ended - and the rate on the deal you are considering.

4. Add the Property Value and Deal Length

The property value is optional and is used to work out your loan to value, which decides which rate band you qualify for. The deal length is how long the new rate is fixed, and sets the period the saving is totalled over.

5. Compare the Two Deals

The result shows both monthly payments, the difference, the saving across the deal period, and the interest each rate costs over the whole remaining term.

Key Formulas Used in the Calculator

Repayment Mortgage Monthly Payment

$M = \frac{P \times r} {1-(1+r)^{-n}}$

P is the balance, r is the annual rate divided by 12, and n is the number of months left. On £180,000 at 6.74% with 20 years to run that gives £1,367.59 a month.

Interest-Only Monthly Payment

$M = P \times r$

Interest only pays the interest and nothing else, so the payment does not depend on the term at all. The same £180,000 at 6.74% costs £1,011 a month, with the capital still owed at the end.

Saving Across the Deal

$\text{Saving} = \text{Monthly Difference} \times \text{Months in the New Deal}$

A £249 monthly saving over a five-year fix is £14,940. Compare that against any product fee and early repayment charge before deciding, since neither is included here.

Loan to Value

$\text{LTV} = \frac{\text{Balance}}{\text{Property Value}} \times 100$

A £180,000 balance on a £300,000 property is 60% LTV. Lower LTV bands unlock better rates, with the best usually at 60% or below.

Benefits

• Compares your current deal and the new one side by side

• Handles both repayment and interest-only mortgages

• Totals the saving across the length of the new deal

• Compares total interest over the whole remaining term

• Warns when the new rate would cost more each month

• Works out your loan to value from the property value

• Compares total interest over the remaining term

When & Where to Use

• Deciding whether to remortgage when a fixed deal ends

• Comparing a low-rate high-fee deal against a higher-rate fee-free one

• Seeing what a rate change is worth across a two or five year fix

• Seeing what falling onto the standard variable rate would cost

• Checking how much a rate change moves your monthly payment

• Working out your loan to value before applying

• Budgeting after a rate rise

Who Should Use This Calculator

The Remortgage Calculator is for homeowners approaching the end of a fixed or discounted deal, anyone already on a standard variable rate, buy-to-let landlords reviewing their financing, and mortgage brokers running quick comparisons.

Tips to Get the Best Deal

Compare the total cost over the deal period, not just the monthly payment

A large product fee can wipe out the benefit of a lower headline rate, so check it separately

Adding fees to the loan means paying interest on them for the whole term

Check for early repayment charges on your current deal before switching

Start looking around six months before your current deal ends

Falling to the standard variable rate is usually the most expensive option

A lower LTV band can unlock a materially better rate, so check where you sit

Pro Tips

• Compare the total cost over the deal period, not just the monthly payment.

• A large product fee can wipe out the benefit of a lower headline rate.

• Adding fees to the loan means paying interest on them for the whole term.

• Check for early repayment charges on your current deal before switching.

• The best rates are usually available at 60% loan to value or below.

• Start looking about six months before your current deal ends.