Buy to let mortgage calculator

Interested in how much you could borrow on a buy to let mortgage - and what your monthly payments might be? Visit our buy to let mortgage calculator for all you need to know.

Property or loan details

Error: Property must be valued at £50,000 or more.

Error: Estimated rental income must be between £1 and £99,999.

Based on your details, you can borrow up to:


This calculator is an estimation of how much you could borrow. If you’re ready to take out a mortgage, speak to a Revolution brokers to see what options are available.

Ltd Company Buy to Let Calculator

As a landlord looking to expand your portfolio, or a new property investor wanting to understand the costs, our buy to let mortgage calculator is a handy tool to help you evaluate which products in the mortgage market are the most competitive.

The calculator is simple to use and has the flexibility to amend the factors to see how each option compares.

Calculating the cost of a HMO buy-to-let mortgage

When you purchase a rental property, your loan-to-value ratio is essential - this is the proportion of the total property value that your mortgage is financing.

Another crucial factor is the term of the loan - the lower the LTV ratio and the shorter the deal on offer, the cheaper the mortgage. Longer-term mortgages cost less per month but tend to be ultimately more expensive, particularly when the fixed-term period ends and the lenders' standard variable rate kicks in.

Buy-to-let mortgages are generally higher risk than lending against residential properties. As such, you will find that the fees and interest rates payable are usually higher, and typically lenders will demand a minimum 20% deposit.

Deciding how much to borrow through a buy-to-let mortgage

Depending on their criteria, most lenders will consider applications where the anticipated rental income is at 125% of the expected mortgage repayments per month.

These criteria vary throughout the market, and other lenders will demand a rental income of 145% and higher, than your monthly payments.

To assess each application, lenders of buy-to-let mortgages use something called a 'managed rate', rather than the actual interest rate chargeable. That rate is usually 5.5%.

As well as the affordability assessments, many landlords will have to meet a minimum turnaround threshold to be accepted.

What would it cost me to take out a £100k rental property mortgage?

Let's look at a scenario - you are buying a buy-to-let property and need a mortgage of £100,000.

An interest rate of 1.39%
Fixed-term of two years
LTV is 60%

On this deal, you might expect to pay a £1,499 arrangement fee, and the total cost over the two years would be £10,974. 

You can use this sort of calculation to apply to rental mortgages with a 25-year term. 

How can I work out the return on a Ltd company buy-to-let mortgage?

Rental properties are a business investment, and so it is crucial to understand what return they would achieve. To help work out your return, you can work on three different bases:

Rental yield
Return on investment
Cash on cash

Calculating rental yield on a buy-to-let property

Rental yield is worked out by taking the rental income per annum, dividing this by the value of the property, and multiplying by 100 to reach a percentage. 

The calculation looks like this: (annual rent/property value) x 100.

For example, a £250,000 property generating £860 a month rent would make a 4.12% rental yield - £10,320 income divided by £250,000 property value, multiplied by 100.

Calculating return on investment for a HMO buy to let purchase

Return on investment, or ROI, is calculated by adding up your total income, less the cost of the purchase, and dividing by that cost. Multiplying this figure by 100 will show you the comparable percentage. Bear in mind that this is a straightforward indicative calculation.

The calculation looks like this: (total earnings/investment cost) / investment cost x 100.

Calculating cash on cash return

Your cash on cash return works out all of the cash costs and income involved. The total money invested includes your deposit, the cost of the purchase, and any other expenses involved in refurbishing the property.

Net annual cash flow is the total rental income you will receive each year, less the cost of your monthly mortgage repayments.

The calculation looks like this: (net annual cash flow/cash invested) x 100.

For example:

If you invest £50,000 as a deposit and spend £10,000 modernising an investment property, your total cash investment is £60,000.

On a buy-to-let mortgage repayment of £350 per month, and rental income of £860 per month, you will make net annual cash flow of £6,120.

This investment, therefore, produces a cash on cash return of 10.2% - £6,120 / £60,000 x 100.

Why returns are relevant on buy-to-let investments

Making sure that your investment will be profitable is essential to a rental landlord. Likewise, being able to compare different rates of return on different products means being able to choose the most cost-effective options. 

What sort of return would I expect to make on a rental investment?

Returns on investment for buy-to-let properties vary significantly in different areas and depending on the demand for rental properties and the average house price at the time you invest.

Typically, the most profitably rental properties in prime UK locations achieve between 6.9%-11.99% rental yield.

How do I choose the best buy-to-let mortgage terms?

Choosing a mortgage is all about considering your circumstances, and selecting the right investment property with the right financing.

Some buy-to-let lender favour experienced landlords, some have particular criteria about the types of property they will lend against, and others do not deal with flats or commercial investments.

To ensure you find the best buy-to-let mortgage and receive independent advice about the most competitive financing deals, give Revolution Finance Brokers a call today, or drop us a line at


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FCA disclaimer

The content included in our articles, blogs, web pages and news publications is based on information accurate at the time of writing. Note that policies and criteria can change regularly throughout the UK mortgage lending market, and it remains essential to contact the consultation team to receive up to date guidance. The information included on the Revolution Brokers site is not bespoke to any circumstances or individual application scenarios and therefore is not intended to be used as financial advice. The content we share is designed to be informative and helpful but cannot be relied upon to provide individual advice relevant to your mortgage requirements. All Revolution team members are fully qualified, trained and experienced to provide mortgage advice of an independent nature. We collaborate with lenders and providers who are regulated, authorised and registered with the Financial Conduct Authority (FCA). Should you require specific mortgage borrowing types, some products such as buy to let mortgages may not be FCA regulated. The Revolution team can provide further information about regulated and unregulated lending as required. Please remember that a mortgage is a debt which is secured against your home or property. Your home can be at risk of repossession if you do not keep up with the repayments or encounter any other difficulties in managing your mortgage borrowing responsibly. This also applies to any remortgage or home loan secured against your property, including equity release products.

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