Landlord Profit Calculator UK 2025

Take your annual rent, subtract everything: mortgage payments, insurance, maintenance, agent fees, ground rent, service charges, void periods, and income tax. What's left is your actual profit. A lot of landlords focus on gross yield and get a nasty surprise when they run the real numbers.

This is the one that changed everything for higher-rate taxpayer landlords. Before Section 24, you could deduct your full mortgage interest from rental income before calculating tax. Now you can't — you get a 20% tax credit instead. So if you're a 40% taxpayer with £10,000 in mortgage interest, you used to save £4,000 in tax. Now you only get £2,000 back. That £2,000 difference comes straight off your profit.

Gross yield of 5–8% is solid. London sits around 3–5% because property prices are so high relative to rents. Northern cities like Liverpool, Manchester, and Nottingham can hit 7–10%+. But gross yield is a vanity metric. Net yield — after mortgage, tax, insurance, maintenance, voids — is what actually matters. A net yield of 3%+ means the property is genuinely making you money.

Agent fees, landlord insurance, repairs and maintenance (but not improvements), ground rent, service charges, accountancy fees, legal fees for tenancy agreements of a year or less, and advertising costs. The big one you can't deduct anymore is mortgage interest — that's Section 24. You still get a 20% tax credit on it, but it's not the same thing.

Gross yield is just annual rent divided by property value. Easy to calculate, but it ignores every cost you actually pay. Net yield subtracts all your running costs, mortgage, and tax before dividing. If someone tells you a property "yields 7%," ask whether that's gross or net. There's usually a 3–4 percentage point gap between them.

Two weeks minimum. City-centre flats in high-demand areas might stay empty for just a few days between tenants. A rural cottage or a quirky property could sit empty for a month or more. Budget 2–4 weeks and you won't get caught out. Every void week costs you a full week's rent plus the bills you're now covering yourself.

It depends on what you're trying to do. Interest-only gives you better monthly cashflow because you're not paying down the capital — but you still owe the full amount at the end. Most buy-to-let landlords go interest-only and plan to sell the property later to clear the debt. Repayment costs more each month but you're building equity. If your goal is long-term wealth rather than monthly income, repayment makes more sense.

Yes. If you already own your home, buying a buy-to-let triggers the 3% additional property surcharge on the entire purchase price. On a £250,000 property, that's an extra £7,500 before you've even started. It's a significant upfront cost that a lot of new landlords underestimate.

The standard rule of thumb is 1% of the property value per year. For a £200,000 property, that's £2,000 — covering boiler servicing, minor plumbing, redecorations between tenants, appliance repairs. Older properties or those with ageing boilers should budget 1.5–2%. One unexpected boiler replacement (£2,500–£4,000) can wipe out half a year's profit.

Full management typically runs 8–12% of monthly rent. On a £1,000/month property at 10%, that's £1,200 a year gone. Tenant-find only is cheaper at 4–6%, but then you're handling maintenance calls, rent chasing, and deposit disputes yourself. Self-managing saves the fee entirely, but you need to know the regulations — there are over 170 pieces of legislation affecting landlords in England.