UK Property — Financial Dashboard

First-time buyer analysis • Adjust all inputs to compare any property
As of March 2026

This calculator models the full financial picture of buying a UK property as a first-time buyer. Enter your salary, property price, and deposit to see mortgage repayments, Stamp Duty Land Tax (SDLT), upfront costs, and whether you qualify for first-time buyer relief.

Planning to rent out spare rooms or list on Airbnb? The tool calculates net rental income after tax — including the Rent-a-Room scheme, Section 24 mortgage interest relief, and the personal allowance taper trap between £100k and £125,140. Adjust pension contributions to see how salary sacrifice can reduce your tax bill.

Compare monthly cashflow, long-term equity growth against a Stocks & Shares ISA alternative, and review key risks before making an offer. All figures use current 2026 UK tax rates and can be adjusted to match any property.

Net Monthly Take-Home
£5,554
After income tax + NI
Min Deposit Needed (at 5x)
£211,450
= price − max mortgage (£483,550)
Monthly Cashflow Surplus
£4,558
After all costs + net rent

Property Price

PROPERTY
Asking price £695,000
Size 121 m²
£/m² £5,744
SDLT £24,750
FTB relief No
Total cash needed ~£250,750

Income

YOUR EARNINGS
Base salary/yr £95,000
Bonus % 1.8% (£1,710)
%
Total gross income £96,710

Mortgage Calculator

SPECIALIST LENDER
Deposit 10% (£69,500)
Mortgage rate 4.50%
Term 25 years
Property price £695,000
Deposit £220,000
Mortgage amount £475,000
LTV 68.3%
Income multiple used 4.91x
Monthly repayment £2,638
Total repaid over term £791,400
Total interest paid £316,400
Mortgage amount exceeds 4.5x income. You'll need a specialist lender or to factor in lodger income. Speak to a broker.

Upfront Costs

Deposit £220,000
Stamp Duty (SDLT) £24,750
Solicitor/conveyancing ~£2,500
RICS survey ~£1,000
Mortgage arrangement fee ~£1,500
Total cash required £250,750

SDLT Breakdown

No FTB SDLT relief — property exceeds the £500k threshold. Standard rates apply.

Rental Income

ACTIVE STRATEGY

Flatmates (long-term)

Room 1 rent/month £1,200
Room 2 rent/month £1,200
Gross (rooms/year) £28,800

Airbnb — Whole Flat (90-day limit)

Whole flat — you're away. Does NOT qualify for Rent-a-Room; always taxed under standard accounting.
Nightly rate £100
Nights let (max 90) 63 nights
Gross Airbnb £6,300
After platform fees (15%) £5,355
Total gross rental/year £34,155

Property Outgoings

COSTS
Service charge/yr −£2,402/yr (£200/mo)
Council tax/yr −£2,100/yr (£175/mo)
Ground rent/yr −£0/yr (£0/mo)
Insurance/mo −£80
Bills (gas/elec/water/internet)/mo −£200
Total outgoings (excl. mortgage) −£655/mo

Tax & Pension

IMPORTANT

Pension (Salary Sacrifice)

Annual contribution £0/yr
Salary after pension £96,710
Income tax + NI saving £0
New net take-home/mo £5,554

Income Tax Breakdown (Employment)

Total income tax £0

National Insurance

Total NI £0

Rental Tax Method

First £7,500 tax-free, no expense deductions allowed.
Taxable rental income £26,655
Adjusted net income £123,365
Exceeds £100k by £23,365
Personal allowance lost £11,683
60% trap: Income between £100k–£125,140 is effectively taxed at 60%. Use the pension slider to reduce below £100k.
Tax on rental (est.) ~£13,800
Net rental after tax ~£20,355/yr
Per month ~£1,696/mo

Monthly Cashflow

PROJECTION

Income

Net salary +£5,554
Net rental (flatmates) +£1,250
Net Airbnb (averaged) +£446
Total monthly income £7,166

Property Costs

Mortgage −£2,638
Outgoings (from above) −£655
Total property costs −£3,293
Monthly surplus
Before living costs
£4,073

ISA Alternative

COMPARISON
Initial ISA Deposit
£
Monthly ISA Contribution
£
ISA Growth Rate
5.0%
Timeframe 10 years
S&S ISA annual allowance is £20,000 (£1,667/mo). Growth is tax-free. Compare against property equity on the chart.
ISA value after 10 years £0
Total contributed £0
ISA growth earned £0

Equity Projection

ILLUSTRATIVE
Compares buying (equity = property value minus mortgage) vs keeping deposit in an ISA with contributions. Dashed orange line = ISA value over time.

Key Risks & Actions

Check the lease — subletting and Airbnb may be prohibited. Leasehold flats often have restrictions. Do this before making an offer.
Lease length — not stated. Under 80 years is costly to extend and affects remortgaging. Verify urgently.
Mortgage consent to let — residential lenders must approve lodgers. Disclose your plan to your broker upfront.
90-day rule — London limits short-term letting to 90 nights/year. You must use the property as your main home for the rest of the year. Ensure your records support this (GP, HMRC, bank).
Tax planning — rental income may push you into the 60% effective rate band (£100k–£125k). Consider salary sacrifice / pension contributions to bring gross income below £100k before renting.
Use a mortgage broker — only a specialist can access 5x+ multiples and lenders who consider lodger income. High street banks alone won't get you there.
Service charge history — £2,402/yr today but request 3 years of accounts. Roof terrace maintenance can be significant.

Cashflow Breakdown

Annual Income Allocation

Pension Contribution Strategy — Avoid the 60% Trap

Without pension contribution
Total income ~£123,000 → 60% effective rate on £23,000 in taper band → ~£13,800 lost
With £23,000 pension contribution
Reduces gross income below £100k → full personal allowance retained → saves ~£9,200 in tax
Recommended action
Ask employer to increase pension via salary sacrifice before you start taking lodger income