Portfolio Target Income
Many landlords have a target: to replace their employment income with rental income, or to generate a specific passive income by a certain age. Working backwards from this goal to determine how many properties are needed — and what capital is required — is essential for structured portfolio growth. This calculator maps a target monthly income to a required portfolio size and capital base.
Why this matters
Without a target, portfolio growth is reactive rather than strategic. Knowing how many properties you need — and what each one costs in capital — creates a roadmap that can be planned and financed systematically.
Key points
- Target income must be set on an after-cost, after-tax basis — not gross rent
- Average net income per property (after all costs except tax) is typically 30–50% of gross rent
- Portfolio size needed increases significantly at low yields or high interest rates
- Capital required per property includes deposit, SDLT, and buying costs — typically 30–35% of property value
- Building a portfolio takes time: lenders restrict rapid portfolio growth
- Consider the management burden — 10 properties may require a letting agent or even a full-time manager
Frequently asked questions
How do I calculate how many properties I need to retire on rental income?
Start with your target monthly income (after all property costs and tax). Divide by the average net monthly income per property (typically £200–£500 for a standard UK buy-to-let). This gives the approximate number of properties needed. Factor in that each property requires capital of approximately 30–35% of value.
What is a realistic net income target per property?
For a typical UK buy-to-let with a 75% LTV mortgage at current rates, net monthly income (after mortgage, management, insurance, and maintenance) is often £100–£400 per property. Higher-yield properties in northern cities can deliver £400–£700. London properties may break even or run at a small loss.
How long does it take to build a property portfolio?
This depends entirely on available capital, income, and credit profile. Using remortgaging and equity release to fund subsequent purchases, many investors add one property per year. Full-time portfolio investors using more sophisticated financing can scale faster.
Are there limits to how many buy-to-let mortgages I can have?
Most high-street lenders limit individual landlords to 3–4 mortgaged properties. Portfolio lenders and specialist providers will lend to landlords with 10, 20, or more properties — but with more rigorous underwriting and potentially higher rates.