Welcome to our second charge mortgage calculator hub. Here you will find a specially designed calculator for working out how much you can borrow and what the repayments would be if you were to secure a second charge mortgage on your home.
You can try our second charge mortgage calculator out below:
What this calculator can tell you
Our second charge mortgage calculator can tell you how much you can potentially borrow on a second charge mortgage, which are also referred to as homeowner loans or secured loans. It will also tell you how much the repayments would be on a loan of this amount.
The calculator bases its results on the amount of equity you hold in your property, the interest rate you select and the product type, among other variables.
How our secured loan calculator works
To work out your affordability for a second charge mortgage (or homeowner/secured loan) first enter your property value and remaining mortgage balance, then input the following:
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Term length: Longer terms mean lower repayments but paying more interest overall
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Rate type: You can choose between fixed-rate and variable rate
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Interest rate: We have defaulted this at 6.5% but you can manually change it for comparison purposes.
Then hit ‘calculate’ and our second charge mortgage calculator will do the rest.
Get impartial secured loan advice today
Example calculations
The tables below show calculations produced by our second charge mortgage calculator tool to provide some contextually relevant examples of this type of borrowing.
1. Variation by Combined LTV (Equity Level)
Lenders use the Combined Loan-to-Value (CLTV) to determine your risk. The more equity you have, the lower the rate.
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Property Value: £400,000
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Existing Mortgage: £220,000 (55% LTV)
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New Loan Amount: £40,000
|
Total Debt |
New CLTV % |
Indicative Rate |
Term |
Est. Monthly Repayment |
|
£260,000 |
65% (Prime) |
6.5% |
15 Years |
£348.50 |
|
£280,000 |
70% (Mid) |
7.1% |
15 Years |
£361.32 |
|
£320,000 |
80% (High) |
8.2% |
15 Years |
£385.58 |
|
£360,000 |
90% (Max) |
9.9% |
15 Years |
£425.21 |
2. Fixed vs. Variable (Product Type)
Variable rates often start lower but carry the risk of rising if the Bank of England reverses its downward trend. Fixed rates provide "inflation protection" for your budget.
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Loan Amount: £30,000
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Loan Term: 10 Years
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CLTV: 70%
|
Product Type |
Initial Rate |
Monthly Repayment |
Total Interest Paid |
2026 Market Outlook |
|
2-Year Variable |
6.5% |
£340.61 |
£10,873 |
Best if further base rate cuts occur. |
|
2-Year Fixed |
6.8% |
£345.16 |
£11,419 |
Budgeting certainty for 24 months. |
|
5-Year Fixed |
7.2% |
£351.27 |
£12,152 |
Locks in current low rates long-term. |
3. The "Term" Trade-off
This table demonstrates how stretching the loan term reduces the monthly "hit" to your wallet but significantly increases the total cost of the debt.
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Loan Amount: £25,000
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Interest Rate: 6.9%
|
Term |
Monthly Repayment |
Total Repayable |
Total Interest |
|
5 Years |
£493.90 |
£29,634 |
£4,634 |
|
10 Years |
£288.94 |
£34,672 |
£9,672 |
|
20 Years |
£192.35 |
£46,164 |
£21,164 |
|
25 Years |
£175.10 |
£52,530 |
£27,530 |
4. Impact of Mortgage Balance on Loan Capacity
Even with a high property value, a large existing mortgage limits your "headroom" for a secured loan.
|
Property Value |
Existing Mortgage |
Max Loan (85% CLTV) |
Est. Rate |
Use Case |
|
£350,000 |
£150,000 |
£147,500 |
7.5% |
Extension / Loft Conversion |
|
£350,000 |
£250,000 |
£47,500 |
8.8% |
Debt Consolidation |
|
£350,000 |
£290,000 |
£7,500 |
10.5% |
Small Home Improvements |
What are the benefits of this calculator?
Using this calculator is a great starting point if you are planning to apply for a secured loan. It is especially designed for this product type and can tell you how much you could potentially borrow on a second charge basis and how much the repayments could be.
Having access to this information can help you budget in advance and give you an idea of the kind of deals you might qualify for. It can also speed up the application process if you already have these numbers to hand when you speak to a lender.
However, keep in mind that all online calculator tools only provide rough estimates and their output isn’t bespoke to you. This is why it’s a good idea to speak to a secured loan broker as the next step, since they can provide personalised calculations and advice based on them.
Why choose Money Helpdesk for your second charge mortgage?
Aside from providing you with bespoke calculations and expert advice about how to act on them, our mortgage brokers are whole-of-market and specialise in homeowner loans.
Here are just some of the reasons why our valued customers choose us:
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Exclusive rates and deals are available
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Our secured loan brokers have access to the entire market
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We are five-star rated on leading review websites
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You can secure an agreement in principle in minutes
Ready to take advantage of a free, no-obligation chat with a mortgage broker who specialises in second charge mortgages? Get started here.
FAQs
Typically, you can borrow from £10,000 up to £500,000+, depending on the equity in your home and your affordability. Most lenders will allow a total debt (CLTV) of up to 85%, though some specialist lenders may go higher.