Properties
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£10k£2m
25%
Deposit: £62,500
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Purchase Price £250,000 The total price you are paying for the property.
Deposit £62,500 25% Deposit = Purchase Price × Deposit %. This is the cash you put down upfront. The remainder is covered by the mortgage.
Stamp Duty £0 0% effective Stamp Duty Land Tax (SDLT) calculated using HMRC bands..
Total Cash Required £0 Deposit + SDLT + Refurb Total Cash = Deposit + Stamp Duty + Refurbishment Cost. This is the total upfront capital you need to complete the purchase and any planned works.
Monthly Payment £0 Mortgage Payment Monthly mortgage payment.
Monthly Cash Flow £0 After all costs Monthly Cash Flow = Monthly Rent × (1 − Void %) − Mortgage Payment − Management Fee − (Insurance + Maintenance + Ground Rent + Service Charge) ÷ 12. A positive number means profit each month.
Gross Initial Yield 0% Rent ÷ Price Gross Initial Yield = (Annual Rent ÷ Purchase Price) × 100. The headline yield based on day-one rent before any costs are deducted.
Net Initial Yield 0% After costs, before mortgage Net Initial Yield = ((Annual Rent − Annual Costs) ÷ (Purchase Price + Acquisition Costs)) × 100. A true net yield using the full cost basis including SDLT and legal fees. Costs include management, insurance, maintenance, ground rent, service charge, and voids — but not the mortgage.
Cash-on-Cash 0% Cash flow ÷ Capital Cash-on-Cash Return = (Annual Cash Flow ÷ Total Cash Invested) × 100. Measures how much cash profit you earn relative to the cash you put in.
ROCE 0% Return on Capital Employed ROCE = ((Annual Cash Flow + Annual Capital Growth) ÷ Total Cash Invested) × 100. Combines rental profit and property appreciation to give the total return on every pound you invested.
Annual Profit £0 Net of all costs Annual Profit = Monthly Cash Flow × 12. This is your total annual rental profit after deducting all running costs and mortgage payments.
Rent-to-Mortgage 0% Rent To Mortgage Rent-to-Mortgage = (Monthly Rent ÷ Monthly Mortgage Payment) × 100.
After-Tax Cash Flow £0 20% taxpayer Monthly cash flow after estimated income tax (Section 24). Mortgage interest cannot be deducted from rental income — instead you receive a 20% tax credit. Higher-rate taxpayers are most affected.

Equity vs Mortgage Balance

Monthly Cash-Flow Breakdown

Cumulative Return Projection

Stamp Duty Breakdown

Stress Testing

What happens to your cash flow if conditions change? Lenders typically stress-test at 5.5–8.5%. Red rows indicate negative cash flow.

Scenario Monthly Payment Monthly Cash Flow Annual Cash Flow vs Base
Your scenario (base) £0 £0 £0 —

10-Year Detail

Year Property Value Equity Mortgage Annual Rent Cash Flow Total Return

25-Year Summary

Year Property Value Equity Mortgage Annual Rent Cash Flow Total Return

Metric Glossary — Understanding Your Investment Numbers

Each metric below plays a specific role in evaluating a buy-to-let property investment. Understanding them together gives you a complete picture of costs, income, and long-term returns.

Metric Formula Why It Matters
Purchase Price Agreed sale price The starting point for every calculation. It directly determines your stamp duty liability, mortgage size, deposit, and yield percentages. Over-paying erodes returns from day one.
Deposit Price × Deposit % The cash you put down upfront. A larger deposit reduces your mortgage and monthly payments but locks up more capital. Most buy-to-let lenders require a minimum 25% deposit.
Stamp Duty (SDLT) HMRC tiered bands + 5% surcharge A mandatory tax on property purchases. For additional properties (most buy-to-lets), a 5% surcharge applies on top of standard rates. This is a significant upfront cost that directly reduces your initial return.
Total Cash Required Deposit + SDLT + Refurb + Legal The total capital you need on day one to complete the purchase. This is the denominator for cash-on-cash and ROCE calculations—it represents everything you have at risk.
Monthly Payment Annuity or interest-only formula Your largest recurring expense. On a repayment mortgage you build equity each month; interest-only keeps payments low but the loan balance never reduces. Use the toggle to compare both strategies.
Monthly Cash Flow Rent − Mortgage − All Costs The money left in your pocket each month after paying the mortgage, management fees, insurance, maintenance, and allowances for voids. Positive cash flow means the property pays for itself; negative means you're subsidising it.
Gross Initial Yield (Annual Rent ÷ Price) × 100 A quick headline metric for comparing properties. It ignores costs, so it's useful for initial screening but doesn't tell you if a deal is actually profitable. Aim for 5%+ in most UK markets.
Net Initial Yield (Rent − Costs) ÷ (Price + Acq. Costs) × 100 A more realistic yield that deducts running costs (management, insurance, maintenance, voids, service charge, and ground rent) and divides by the total acquisition cost (purchase price + SDLT + legal fees). This gives a true net return on your full cost basis, and lets you compare properties regardless of how they're financed.
Reversionary Yield Post-Refurb Rent ÷ (Price + Refurb) × 100 The expected gross yield after refurbishment, using the higher achievable rent divided by the total investment including capex. This shows the return once works are complete and the property is re-let at its improved value. Only applicable when a refurb cost and post-refurb rent are entered.
Cash-on-Cash Return (Annual Cash Flow ÷ Total Cash Invested) × 100 The most important metric for leveraged investors. It measures the annual cash profit as a percentage of the actual cash you put in—not the property price. A 10% cash-on-cash means you earn 10p for every £1 invested each year. It reveals the true power of using a mortgage to amplify returns.
ROCE (Cash Flow + Equity Gain) ÷ Capital Employed × 100 Return on Capital Employed gives the fullest picture. It combines rental profit and capital growth (property appreciation + mortgage paydown) relative to your invested capital. A high ROCE means your money is working hard across both income and growth. Particularly useful when comparing property against other investments like stocks or bonds.
Annual Profit Monthly Cash Flow × 12 Your total yearly rental profit after all expenses. This is the cash that ends up in your bank account (before tax). Use this to assess whether the investment meets your income goals and to plan for future acquisitions.
Rent-to-Mortgage (Monthly Rent ÷ Monthly Mortgage) × 100 A stress-test ratio popular with lenders. Most require 125%–145% coverage, meaning rent must exceed the mortgage payment by that margin. Below 125% may make it harder to secure financing. Above 150% signals a comfortably self-funding investment.