Landlord calculator
Rental yield, cash flow, stamp duty and estimated tax on a buy-to-let.
Monthly cash flow before tax
£143.27
£114.62 a month after estimated tax · return on cash 2.17%
- Gross yield
- 6.6%
- Net yield
- 4.98%
- Mortgage per month
- £687.50
- Loan to value
- 75%
- Rent per year (after empty weeks)
- £12,692.31
- Running costs per year
- £2,723.08
- Tax per year (estimate)
- £343.85
- Cash you put in
- £63,300.00
- Stamp duty
- £11,500.00
Show workings
- Rent after empty weeks£1,100.00 × 12 × (52 − 2) ÷ 52 = £12,692.31
- Running costsAgent £1,523.08 + other costs £1,200.00 = £2,723.08
- Mortgage£150,000.00 × 5.5% ÷ 12 = £687.50 a month
- Cash flow£12,692.31 − £2,723.08 − £8,250.00 = £1,719.23 a year
- Tax (Section 24)20% × £9,969.23 − 20% × £8,250.00 interest = £343.85
- Stamp duty5% on £125,000.00 + 7% on £75,000.00 = £11,500.00
- Gross yield£13,200.00 ÷ £200,000.00 = 6.6%
How it works
Rental income allows for empty weeks between tenants. Running costs are the letting agent plus insurance, repairs, service charge, safety checks and anything else. Cash flow is what's left after the mortgage.
Gross yield = yearly rent ÷ price. Net yield takes off running costs (but not the mortgage). Return on cash compares your after-tax cash flow with the money you put in (deposit, stamp duty and other purchase costs).
Tax (UK): since 2020, individual landlords can't deduct mortgage interest; instead they get a tax credit of 20% of it. So the estimate is your tax rate × profit before mortgage interest, minus 20% of the interest. Higher-rate taxpayers often pay more than they expect.
Stamp duty is estimated for England and Northern Ireland, including the 5% surcharge on additional properties (rates checked November 2026). For Scotland or Wales, or a limited company purchase, turn off the estimate and enter your figure.
Worked example
A £200,000 flat with a £50,000 deposit and a £150,000 interest-only mortgage at 5.5% costs £687.50 a month. At £1,100 rent with two empty weeks, a 12% agent and £1,200 of yearly costs, the cash flow is about £143 a month before tax. Gross yield 6.6%; stamp duty with the surcharge is £11,500.
Questions
What is a good rental yield?
Many investors look for a gross yield of 5–8% in the UK, but it varies widely by area: cheaper areas often yield more but grow in value less. Net yield and cash flow after tax matter more than gross yield.
Is this tax figure accurate?
It's an estimate for an individual landlord paying tax at one rate. Your rental profit adds to your other income and can push you into a higher band; allowances, losses and company ownership change the picture. Check with an accountant.
What should I budget for repairs?
A common rule of thumb is 5–10% of the rent, more for older properties. Also budget for gas safety (yearly), electrical checks (every five years in England) and any licensing.