Poqet

Rental Portfolio Calculator UK

Last Updated: 15 June 2026

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Your rental portfolio

Add each property — up to 12. Click Calculate to see the aggregate analysis.

#Address / refTypeValueMortgage Monthly rentRunning costsPre-tax CF/moGross yield
Portfolio income & yield
Portfolio debt & equity
Cash flow summary
Portfolio ICR
Rate scenarioPortfolio monthly interestTotal CF/moProperties cash-flow negativePortfolio ICRStatus
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What the portfolio calculator shows

Individual property calculators give you a single-property view. This tool aggregates the entire portfolio — showing you the numbers that matter at scale: total monthly income, combined debt exposure, overall cash flow resilience, and how a rate rise affects every mortgage simultaneously.

Portfolio ICR — the number lenders care about

Since the PRA introduced stricter portfolio landlord rules in 2017, most lenders require borrowers with 4 or more mortgaged BTL properties to pass an aggregate ICR test across their entire portfolio — not just the property being mortgaged. If your portfolio's combined rental income doesn't adequately cover combined mortgage interest at the required stress rate, lenders can decline new borrowing even if the individual property being mortgaged would pass in isolation.

The portfolio ICR is calculated as: total annual rental income ÷ total annual mortgage interest at the stress rate × 100. Most lenders require this to be at least 125–145% depending on your tax position.

Stress testing your portfolio

The stress test section shows what happens to your total monthly cash flow and portfolio ICR when mortgage rates rise by 0.5%, 1%, 2%, and 3% above current levels. Properties that turn cash-flow negative in a rate rise scenario are highlighted — these represent your portfolio's vulnerabilities, and knowing about them before they happen allows you to take action: overpay, remortgage to fix rates, or dispose of underperforming assets.

Frequently asked questions

How do I calculate my rental portfolio yield?
Portfolio gross yield = (Total annual rent across all properties) ÷ (Total portfolio value) × 100. The calculator above computes this automatically once you enter all properties. A portfolio with mixed high-yield northern properties and lower-yield southern properties will produce a blended average — drill into individual property yields to identify which assets are dragging down the portfolio average.
What is a portfolio landlord under UK mortgage rules?
A portfolio landlord is defined as having 4 or more mortgaged BTL properties. Since 2017, lenders must assess the entire portfolio ICR when a portfolio landlord applies for a new BTL mortgage or remortgage. This means: you must declare all existing BTL properties; lenders stress-test all mortgages simultaneously; and a weak property elsewhere in the portfolio can affect your ability to borrow on a strong new deal.
Should I use a spreadsheet or this calculator for my portfolio?
This calculator is designed for a quick aggregate overview and stress test — it's faster than a spreadsheet for scenario analysis. For detailed ongoing tracking (monthly income, repairs, voids, tax returns), a dedicated landlord accounting tool or spreadsheet is better suited. Use this calculator to quickly check portfolio ICR before applying for a new mortgage, to stress-test your exposure before a rate rise, or to compare the blended yield across your properties.

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DisclaimerAll calculations are estimates for illustrative purposes only. Running costs and void rates are approximations. Tax calculations use simplified models and do not constitute tax advice. Lender ICR requirements vary — always verify with a qualified mortgage broker before applying.

About the author

Kelvin Peltier

Retail leader, entrepreneur and founder of Poqet.io.

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✓ Editorially reviewed — all Poqet guides are checked for factual accuracy before publication and updated when UK rates or legislation change. Editorial Policy