HMO Yield Calculator: How to Assess a Multi-Let Deal

2026-06-22

HMOs promise headline yields that make single buy-to-lets look pedestrian. A well-run 5-bed HMO can deliver 10-14% gross where a comparable single let might manage 6-7%. But the gap between gross and net is wider on an HMO than any other property type, because the costs are significantly higher and more complex.

The investors who make money from HMOs are the ones who calculate yield honestly — including every cost that multi-let properties carry and single lets don't. This guide shows you how to do that calculation properly.

HMO Yield: The Core Calculation

The formula is the same as any property — but the inputs are different:

Gross Yield = (Total Annual Room Rents / Property Purchase Price) x 100

Net Yield = ((Total Annual Rents - All Annual Costs) / Total Investment) x 100

The difference with HMOs: you're adding up individual room rents (not a single tenancy rent), and your cost base is significantly larger.

Room-by-Room Income

Each room in an HMO commands its own rent. Factors that affect room pricing:

Typical room rents by city (2026):

The Cost Stack: What HMOs Pay That Single Lets Don't

This is where most HMO yield calculations go wrong. Investors apply single-let cost assumptions to a multi-let property and wonder why the actual return is lower than projected.

Bills (Landlord-Paid)

Most HMOs include bills in the room rent. Tenants expect it. This means YOU pay:

:::stats £5,400-£9,200 | Annual Bills (5-Bed HMO) £90-£153/room | Monthly Bill Cost Per Room :::

[!warning] Energy costs are the wildcard Since the 2026 energy shock, gas and electric costs for HMOs have been volatile. Budget conservatively. An uninsulated Victorian HMO with 5 tenants all running heaters independently can easily exceed £4,000/year in energy costs alone.

Management

HMOs are management-intensive. Turnover is higher (rooms let individually, tenants come and go), maintenance requests are more frequent (5 tenants means 5x the contact), and compliance requirements are ongoing.

• Professional HMO management: 12-18% of rent (higher than the 8-10% for single lets)
• Self-management time: realistically 5-10 hours/month for a 5-bed HMO

Compliance Costs

For full licensing details, see HMO Licensing Requirements UK 2026.

Higher Maintenance

More tenants = more wear and tear. Budget higher than a single let:

• Single let: 10% of rent for maintenance
• HMO: 15% of rent is more realistic (more bathrooms, shared kitchen, higher turnover repairs)

Void and Turnover Costs

Individual rooms have higher turnover than whole houses. The average HMO room is re-let every 10-14 months. Each turnover means:

• Cleaning (£50-£100 per room)
• Touch-up decoration (£50-£150)
• Potential void period (1-3 weeks between tenants)
• Marketing/referencing costs (£50-£100)

Budget 8-10% void/turnover allowance on total rent (vs 4-5% for a single let).

Furniture and Communal Items

HMOs are almost always let furnished. You're providing beds, wardrobes, desks, chairs, and communal furniture. This depreciates and needs replacing:

• Initial furnishing: £1,000-£2,000 per room
• Annual replacement allowance: £200-£400 per room

Worked Example: 5-Bed HMO

Property: 5-bed Victorian terrace, purchased for £180,000. Refurbished to HMO standard for £35,000. Rooms rented at £500/month each.

Annual Income: 5 rooms x £500 x 12 = £30,000

Annual Costs:

Results:

:::stats 16.7% | Gross Yield 12.1% | Net Yield (Before Mortgage) £182/mo | Net Cashflow 2.7% | Cash-on-Cash Return :::

That 16.7% gross yield became 2.7% cash-on-cash. The costs ate most of the premium. It's still better than a single let (which might produce 1-2% cash-on-cash at the same price point), but it's nowhere near the 16% that the headline number suggests.

[!tip] The real HMO advantage appears over time As rents grow and the mortgage stays fixed, HMO cashflow improves faster than single lets because the income base is larger. A 5% rent increase on £30,000 is £1,500/year. On a single let at £12,000, it's only £600.

When HMOs Beat Single Lets

Despite higher costs, HMOs win when:

• Room rents are strong relative to property price (high yield areas)
• You self-manage (saving the 15% fee turns the numbers significantly)
• The property is already configured for multi-let (minimal conversion cost)
• Bills are manageable (good EPC rating, efficient heating)
• Tenant demand is deep (university towns, professional centres)

When Single Lets Win

HMOs lose their advantage when:

• Conversion costs are high (£40,000+ to convert a house)
• Licensing requirements add excessive compliance burden
• The area has weak room demand (long voids between tenants)
• Energy costs are uncontrollable (poor insulation, old heating)
• You're paying premium management fees and can't self-manage

Run Your Own HMO Numbers

The HMO Yield Calculator lets you model a multi-let deal room by room. Input individual room rents, set your cost assumptions for bills, management, and compliance, and see the actual yield and cashflow — not the fantasy headline number.

:::tool hmo-yield Calculate Your HMO Yield :::

For comparison with a single let at the same price point, run the property through the Deal Analyser as a standard BTL to see the difference.

:::tool deal-analyser Compare HMO vs Single Let :::

Summary

• HMO gross yields (10-14%) are significantly higher than single lets (5-7%)
• But costs are 2-3x higher: bills, higher management, compliance, furniture, turnover
• Net cashflow after ALL costs is typically £150-£400/month on a 5-bed HMO
• Always calculate with landlord-paid bills, 15% maintenance, and 10% void allowance
• The real HMO advantage is portfolio-level: higher income base means faster growth over time
• Self-management dramatically improves the economics (saves 15% of gross rent)

Don't be seduced by the gross yield. Run the full numbers. If the deal works with honest cost assumptions and conservative rent estimates, it works. If it only works with optimistic room rents and understated bills, it doesn't.

Costs and rents in this guide are estimates based on 2026 UK market data. Always research local room rents, utility costs, and licensing requirements for your specific area before committing to an HMO purchase.