Houses in Multiple Occupation (HMOs) are a powerful way to boost rental income, but the mortgage side can get complex.
Our HMO Mortgage Calculator gives you a fast estimate of how much you could borrow based on your expected rental income, how much rent you need to meet lenders’ stress tests, and what kind of yield you’re likely to achieve.
Whether you’re buying your first HMO or expanding a portfolio, this tool helps you plan your deal with confidence.
Calculate mortgage affordability for House in Multiple Occupation investments
| Item | Monthly | Annual |
|---|---|---|
| Gross Rental Income | £2,250 | £27,000 |
| Mortgage Payment | £1,755 | £21,060 |
| Management Costs | £300 | £3,600 |
| Net Cash Flow | +£195 | +£2,340 |
HMO mortgages typically require 25% minimum deposit, stress testing at higher rates, and 125-145% rental coverage.
Alex’s 2-year fix is ending, and he’ll be moved to 7.25% SVR. Using the calculator, he compares this to a 5.15% remortgage deal and sees a saving of £210/month.
Dan and Priya want to borrow an extra £20,000 for home improvements. The calculator shows how that affects their monthly payment and total interest, so they can budget with confidence.
Ellie is looking at two new mortgage deals — one with a fee, one without. Using the calculator, she sees that even with a £999 fee, the lower interest rate saves her money within 18 months.
A: ICR (Interest Cover Ratio) is how much your rent must exceed your mortgage interest. For example, 125% ICR at 5.5% means your rent must be 125% of the interest due at a 5.5% rate.
A: HMO properties often involve higher risk, voids, and management, so lenders use stricter stress testing to ensure long-term affordability.
A: Yes — just choose the appropriate ICR (usually 125%) for Ltd company buy-to-lets. Some lenders will even stress test at 100% for professional landlords.
A: No — this is an affordability tool only. For full deal costings, speak to us for a tailored mortgage illustration.
A: Not directly, but the affordability approach is similar. Contact us for advice on MUFBs or semi-commercial lending.
Use our free HMO Mortgage Calculator to check the numbers — then speak to Mortgage Knight for expert advice, lender match-ups, and fast decision-in-principle support.
We help investors unlock more borrowing, better rates, and stress-free completions — even on complex cases
