The first question in any secured loan conversation is “what would this cost me each month, and how much would I pay back in total?” The answer depends on three things: the amount you borrow, the term you choose, and the APR you are offered. Changing any one of them shifts the picture significantly. A £25,000 loan at 7% APR costs £495 per month over 5 years but £290 per month over 10 years, with the longer term more than doubling the total interest from around £4,700 to around £9,800. This calculator lets you work through those trade-offs before speaking to a lender or broker.
For more detailed analysis, including checking your equity position, comparing fixed versus variable rates, or modelling early repayment scenarios, the specialist calculators linked below each focus on a specific question. All figures on this page are illustrative and the tool does not constitute financial advice.
At a Glance
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The term comparison table is the most useful output for most people.
It shows the monthly payment and total interest cost at five common term lengths simultaneously, so you can see the trade-off between lower monthly payments and higher total interest without adjusting the slider back and forth. The highlighted row shows your selected term, and the rows above and below show what shortening or extending would cost.
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The APR is illustrative. The rate you are offered depends on your individual circumstances.
Secured loan rates in the UK typically range from around 4% to 16% APR depending on the loan amount, LTV ratio, term, and credit profile. Lenders assess these factors individually. The APR slider lets you model different rate scenarios to see how sensitive the monthly payment is to the rate offered.
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Eight specialist secured loan calculators cover every angle of the decision.
This page covers the core repayment calculation. The specialist tools below cover equity and LTV, borrowing power, affordability, fixed vs variable rates, early repayment charges, overpayment impact, and comparisons against remortgaging and further advances.
Interactive tool
Secured loan calculator
Calculate your monthly repayment and total cost, find the shortest affordable term, see how rate changes affect the payment, and model overpayment savings.
All figures are illustrative. The APR you are offered depends on your individual circumstances.
Monthly repayment
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per month
How the term affects cost
| Term | Monthly | Total repayable | Total interest | Interest as % of loan |
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Affordability-led term finder
Set the maximum you can comfortably afford per month. The tool finds the shortest term that fits, which minimises total interest.
Rate sensitivity: what if the APR is different?
Overpayment quick model
What happens if you pay a little extra each month from day one
All figures use the standard annuity formula (reducing balance, monthly compounding). The APR is illustrative; secured loan rates in the UK typically range from around 4% to 16%. The affordability term finder identifies the shortest term where the payment fits your budget. The overpayment model assumes no early repayment charges; check your lender’s terms before overpaying. Your home may be repossessed if you do not keep up repayments on a secured loan. This tool does not constitute financial advice.
How the calculator works
Enter the loan amount, choose a term in years, and set an illustrative APR. The calculator uses the standard annuity formula (reducing balance, monthly compounding) to produce the monthly repayment, total amount repayable, and total interest paid. The principal vs interest bar shows the proportion of each pound repaid that goes towards the original loan versus interest, which changes significantly with the term length.
The term comparison table is the most practical output. It shows the monthly repayment and total interest at 3, 5, 7, 10, 15, 20, and 25 years simultaneously, with your selected term highlighted. This makes the core trade-off visible: shorter terms cost more each month but save thousands in total interest, while longer terms are easier to manage monthly but cost more overall. The guide to APR on secured loans explains how the rate is calculated and what drives the rate you are offered.
Understanding APR on secured loans
The APR (annual percentage rate) includes the interest rate and any mandatory fees, standardised to allow comparison across products. The rate you see advertised is a “representative” APR: lenders are required to offer that rate to at least 51% of successful applicants, which means up to 49% may be offered a higher rate based on their credit profile, LTV, or loan size. The APR band cost comparator shows how different rate tiers affect the total cost of the same loan, which is useful if you have been quoted a rate and want to see where it sits relative to the market.
Secured loan rates are generally lower than unsecured loan rates for the same borrower because the lender has security over the property. However, the total interest paid on a secured loan can be higher because the terms are typically longer. A £25,000 unsecured loan at 9% over 5 years costs approximately £6,100 in interest. The same amount as a secured loan at 7% over 15 years costs approximately £15,400 in interest despite the lower rate. The secured vs unsecured threshold tool models this crossover point for any given amount and rate combination.
Show the working
Unsecured: £25,000 at 9% APR over 5 years
Secured: £25,000 at 7% APR over 15 years
The secured loan costs £9,310 more in total interest despite the lower APR, because the 15-year term means interest accrues for three times as long. Both figures use the standard annuity formula. Monthly payments shown to two decimal places. Totals rounded to the nearest pound. APRs are illustrative.
All secured loan calculators
Each of these tools focuses on a specific question in the secured loan decision. Use them individually or in combination depending on where you are in the process.
Equity position
LTV and equity calculator
Enter your property value and mortgage balance to see your available equity and the maximum you could borrow at each LTV threshold from 70% to 90%. Open tool
Borrowing capacity
Borrowing power calculator
See the maximum you could borrow based on equity and affordability constraints, with an LTV tier staircase and rate sensitivity panel. Open tool
Monthly budget
Monthly affordability checker
Model a proposed loan payment against your income and outgoings, with stress tests for rate rises, to check it fits your budget. Open tool
Rate structure
Fixed vs variable rate comparator
Compare a fixed rate loan against a variable rate equivalent across different rate movement scenarios to see which costs less overall. Open tool
Leaving early
Early repayment charge calculator
Estimate the ERC at any point in the term to see whether paying off early makes financial sense after the penalty is factored in. Open tool
Paying extra
Overpayment impact calculator
See how regular overpayments or a one-off lump sum reduce your loan term and total interest, with ERC threshold modelling. Open tool
Compare options
Second charge vs further advance
Compare the cost of a second charge mortgage against a further advance on your existing mortgage to see which delivers the better deal. Open tool
Compare options
Secured loan vs remortgage
Model both options side by side to see which costs less in total when you need to raise additional funds against your property. Open tool
Not sure what to look at next?
All of our secured loan guides and tools in one placeFrequently asked questions
Why does a longer term cost so much more in total interest?
Because interest is charged on the outstanding balance each month, and a longer term means the balance reduces more slowly. On a 5-year term, the principal is being paid down rapidly and each month’s interest charge falls with it. On a 15-year term, the monthly payment is lower but a larger proportion of each payment goes to interest rather than principal, especially in the early years. The term comparison table shows this directly: the total interest column typically doubles or triples as the term extends, even though the monthly payment falls.
This is the central trade-off in any secured loan decision. A shorter term costs more each month but saves significantly in total interest. A longer term is easier to manage month to month but costs more overall. The right balance depends on what you can comfortably afford each month after accounting for your other commitments. The affordability checker helps test this against your actual income and outgoings.
What APR am I likely to be offered?
The rate depends on several factors: the loan amount, the loan-to-value ratio (how much equity remains in your property after the loan), the term, and your credit profile. Borrowers with strong credit, low LTV, and straightforward circumstances typically access the lower end of the range. Borrowers with adverse credit history, higher LTV, or non-standard income may be offered rates towards the higher end. The credit profile classifier gives an indication of which lender tier your profile is likely to fall into.
The advertised “representative” APR is the rate offered to at least 51% of successful applicants. You may be offered a different rate. Using a soft-search eligibility check before making a formal application shows you the rate you are likely to be offered without affecting your credit file. The APR band cost comparator shows how different rate tiers affect the total cost of the same loan.
How much can I borrow with a secured loan?
The maximum depends on two constraints: how much equity you have in your property (the LTV ceiling) and how much you can afford to repay each month (the affordability assessment). Most mainstream lenders offer secured loans up to 85% combined LTV, meaning the existing mortgage plus the new loan cannot exceed 85% of the property value. Some specialist lenders will consider up to 90% or occasionally higher, though at noticeably higher rates.
The LTV and equity calculator shows your borrowing ceiling at each LTV threshold. The borrowing power calculator combines both the equity ceiling and the affordability ceiling to show the binding constraint and routes to increase it.
Is this calculator accurate enough to use for planning?
It uses the standard annuity formula that lenders use for repayment calculations, so the monthly payment and total interest figures are mathematically accurate for the inputs provided. The main limitation is the APR: the rate you enter is illustrative, and the rate you are actually offered will depend on your individual circumstances. For planning purposes, modelling at two or three different APR levels gives a realistic range. The figures are consistent with those a broker would use for initial discussions.
The calculator does not include arrangement fees, valuation fees, or broker fees, which would add to the total cost of borrowing. Our guide to secured loan fees covers the full cost structure including all fees that may apply.
Squaring Up
The monthly repayment and the total interest cost are the two figures that matter most at the planning stage, and the term comparison table makes the trade-off between them visible in a single view. A shorter term always costs less overall but requires a higher monthly commitment. The right balance is personal and depends on what fits comfortably within your budget after other commitments are accounted for.
For borrowers who want to go deeper, eight specialist secured loan calculators are linked from this page, each focusing on a specific question: checking equity and LTV, testing affordability, comparing rate structures, modelling early repayment and overpayment scenarios, and comparing a secured loan against a remortgage or further advance. Together they cover every angle of the secured loan decision before a formal application is submitted.
Continue your research
Guides, calculators, and comparators covering every aspect of secured lending Explore guides and toolsIntro Paragraph – Show the working
£25,000 at 7% APR over 5 years
£25,000 at 7% APR over 10 years
Calculated using the standard annuity formula at a fixed 7% APR. Monthly payments shown to two decimal places. Totals rounded to the nearest pound. The APR is illustrative — the rate offered will depend on the lender and your individual circumstances.
This tool is for illustrative purposes only and does not constitute financial advice. All figures are calculated using the standard annuity formula and assume a fixed rate for the full term. The APR shown is illustrative; the rate you are offered will depend on your individual circumstances and the lender’s assessment. The calculator does not include arrangement fees, valuation fees, or broker fees. Your home may be repossessed if you do not keep up repayments on a secured loan. Actual outcomes will depend on your individual circumstances.
