How much can I borrow for my buy-to-let mortgage?

If you’re wondering how much you can borrow on a buy-to-let mortgage, our simple calculator can help to give you an estimate. Simply enter your proposed monthly rent details and stress test rate before hitting the ‘calculate’ button.

Please note that this calculator is only designed to give you a rough estimation. Your personal financial circumstances and credit history will be assessed by a lender when you apply for a buy-to-let mortgage. When assessing whether an applicant can afford a buy-to-let mortgage, a lender ‘stress tests’ an application against mortgage rates rising to up to 5.5%, to protect against unexpected cost increases for landlords.

If you need more help and have questions on taking out a buy-to-let mortgage, talk to our experts at iam mortgages today. They will discuss your current financial circumstances with you, and will be able to advise on the right products and lenders for your situation.

Buy-to-Let Mortgage Calculator



    Your guide to mortgage eligibility

    You will be eligible for a mortgage based on several criteria that every mortgage lender will take into consideration. These criteria are outlined below:

    Financial deposit

    This is the sum you need to put down on a property to secure it. You will need at least 10% of the house value to put down as a deposit. For first time and other specialist buyers, there are schemes available (such as Help to Buy) where you can put down just 5% deposit if you meet the lending criteria.


    Lenders favour younger people, as the younger you are, the more time you have to pay off your mortgage, so your monthly repayments will be lower and you'll be able to borrow more over a longer period of time.


    Lenders will be more willing to let you borrow a larger mortgage if you earn a higher salary, as they will (in theory) have more chance of receiving their monthly payments on time without any issues. If you are purchasing a property with another person such as a spouse, a lender will consider and evaluate both parties' salaries.

    High expenditure

    If you have racked up large credit card bills and struggle to pay them off, a mortgage lender will not look on this favourably and might not let you borrow as much as you would like. You will need to curb this habit if you plan to take out a large sum as a mortgage.

    Credit score

    A mortgage is effectively a loan, so your credit score will be crucial in determining how much you can borrow from a lender. Paying things like credit cards off on time, being on the electoral register and being completely out of debt are ways to improve your credit score. You can assess your credit score for free online.

    What's next?

    Get in touch with our expert advisers to discuss your options.