Finance tool · Free, no signup
HMO Mortgage Calculator UK 2026 (ICR Stress Test)
Work out the maximum HMO mortgage your room income supports, using the lender’s interest coverage ratio (ICR) stress test. Models per-room rent, void allowance, basic vs higher-rate vs Ltd company ICR, and stress rates from 5.5% to 8% used by major HMO lenders in 2026.
HMO inputs
Your tax position
Specialist HMO lenders typically stress at 5.5% for 5-year fixes and 7%–8% for shorter fixes or large (7+ room) HMOs. Some lenders apply ICR up to 170% for higher-rate landlords on personal-name HMO mortgages.
Stress test result
Passes HMO stress test
Required annual rent (after voids): £22,330
Effective annual rent (after voids): £34,500
Maximum loan at this room income
£432,602
5 rooms × £625/mo, 8% voids, ICR 145%, stress rate 5.5%.
Gross annual room income£37,500
Less voids (8%)− £3,000
Effective annual rent£34,500
Stressed monthly interest (loan × rate ÷ 12)£1,283
ICR multiplier× 1.45
= required annual rent£22,330
Indicative only. Specialist HMO lender criteria vary widely (top-slicing, large-HMO uplifts, Article 4 area surcharges, commercial valuations for 7+ rooms). Always verify with a specialist broker. See the PRA SS13/16 supervisory statement for the underlying buy-to-let underwriting framework.
Save your scenarios
Want to save, share and compare?
LetCompliance tracks every property in your portfolio alongside these numbers, plus rent, deposits, certificates and more, so you're never recalculating from scratch. 14-day free trial, no card needed.
Start free trialOther tools