HMO valuation calculator
This HMO valuation calculator estimates what a house in multiple occupation could be worth on its rental income and compares it with its value as an ordinary house. Enter your own rents, costs and yield to see both figures and the gap between them.
Reviewed by David Sampson, Founder & Director · Created 19 October 2026 · Last reviewed 19 October 2026
Count only rooms that meet minimum room sizes.
Monthly rent for one let room.
Share of gross rent lost to empty rooms. Leave blank for none.
Bills, management, licence, insurance and maintenance.
The net yield investors accept for similar HMOs locally; a valuer or local agent can tell you.
What similar ordinary houses sell for.
Only for the illustrative loan on each basis.
Planning estimate, not a valuation or a lender decision.
Lenders choose the valuation basis; many use the bricks-and-mortar value for small HMOs.
What does an HMO valuation calculator show?
An HMO valuation calculator estimates two values. The investment value capitalises the net rent the house earns, by dividing it by a yield that investors accept locally. The bricks-and-mortar value is what the house would sell for as an ordinary home. The gap between them shows how much the HMO use may add.
Every input is yours: the calculator holds no market rents, yields or costs, and shows a result only once you enter a yield and a bricks-and-mortar value. The result is a planning estimate, not a valuation or a lender decision.
How are HMOs valued?
Valuers use two main approaches for HMOs. Smaller HMOs are often valued on comparable house sales, with the rent checked for sustainability. Larger or purpose-converted HMOs may be valued as investments, by capitalising the sustainable net rent at a market yield. Valuers also allow for licensing and compliance costs, and may exclude rooms below minimum sizes.
Both approaches are set out in the RICS professional standard on valuing buy-to-let and HMO properties (2nd edition). The investment method is often called a commercial valuation of an HMO, because it values the house like a business on its income. Planning status matters too: Article 4 and sui generis status can change which basis a valuer uses. These rules are for England; the rest of the UK differs.
Worked example
This worked example uses example figures, not market data. Six rooms let at £650 a month each give £46,800 a year. Allow 5% for empty rooms and £12,000 a year for running costs, leaving net income of £32,460. At an 8% yield the investment value is £405,750. If similar houses sell for £300,000, the HMO use adds about 35%.
For example, with the same inputs (example figures, not market data), the calculator gives these results too. On the same £300,000 house value, the gross yield is 15.6% and the net yield 10.82%. A small change in the yield moves the investment value a lot.
Which value will a lender use?
The lender decides which basis its valuer uses, not the borrower. Many lend on the bricks-and-mortar value for small HMOs, and only some accept an investment value, sometimes capped against the vacant-possession figure. The valuer's rental figure also feeds the lender's rent test, so a lower valuation can reduce the loan twice.
The HMO mortgage calculator shows what loan the rent could support. That rent test compares the rent with the mortgage interest at a stressed rate, using a cover ratio each lender sets for itself.
Which lenders accept an investment valuation, and on what size of HMO, varies and changes often. Some set a minimum number of rooms, and some only use it for larger or purpose-converted houses. Ask about the valuation basis before you pay for a survey, because it can decide whether a purchase or refinance works and how much deposit you need. If the basis is unclear or the lender will not say, brokers who handle HMO cases can check which lenders fit your house.
Frequently asked questions
How do you value an HMO property?
A valuer either compares the house with sales of similar homes nearby, or values it as an investment by dividing its sustainable net rent by a local market yield. The lender's valuer chooses the approach, usually by the size of the HMO.
What is a commercial valuation for an HMO?
A commercial valuation values an HMO on its income rather than on house prices. The valuer works out the sustainable net rent after empty rooms and running costs, then divides it by a yield investors accept locally. It is used more often for larger HMOs.
Is an HMO worth more than a normal house?
Sometimes, if it is valued on its rent and the rent is strong. Many HMOs, especially smaller ones, are valued on comparable house prices, so the HMO use adds little to the figure a lender works from. Where an investment valuation is accepted, the gap can be large.
Who pays for an HMO valuation?
The borrower usually pays for the lender's valuation, because it is part of the mortgage application. HMO valuations tend to cost more than standard ones, because the surveyor checks the layout, room sizes and licensing.
Does a lender have to use the investment value?
No. The lender sets its own valuation rules, and many use the bricks-and-mortar value for smaller HMOs whatever the rent. Some accept an investment value for larger or purpose-converted houses, sometimes with limits.
Can a valuer leave rooms out of an HMO valuation?
Yes. If a room let for sleeping is smaller than the national minimum, such as 6.51 m² for one adult (SI 2018/616), a lender's valuer may exclude it from the room count and the rental figure (lender criteria, accessed 19 Oct 2026). That lowers both the investment value and the rent the lender tests.
How accurate is an HMO valuation calculator?
Only as accurate as the figures you enter. The calculator applies the standard income method to your rent, costs and yield, but a valuer also weighs local evidence, the condition of the house, licensing and demand. Use it to compare scenarios, not instead of a valuation.
Related articles
Practical guides and explainers from our blog — relevant to this mortgage type.
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Planning Refusals for HMOs Surge: Impact on the Mortgage Market
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HMO Planning Refusals Double: Impact on the Mortgage Market
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Assumptions
Updated 2026-10-19Gross rent is rooms times rent per room times 12.
Net income is gross rent, less the empty-room allowance, less running costs.
Investment value is net income divided by the yield you enter.
Nothing is pre-filled. Rents, costs, yield and LTV are your own figures.
The method follows the investment approach in the RICS standard for valuing buy-to-let and HMO properties. It is a simple estimate, not a RICS Red Book valuation.
Important: Your home may be repossessed if you do not keep up repayments on your mortgage. Information on this page is for general guidance only and does not constitute financial advice.Always verify details directly and seek independent advice before making financial decisions.