Mortgage Calculator with Stamp Duty 2025/26

Reviewed by Mustafa Bilgic
UK Calculator Editor · Updated May 2026

Why a mortgage calculator without SDLT and fees lies to you

Most calculators show the deposit and the monthly payment but ignore the £6,000–£10,000 of fees that hit a typical first-time buyer on completion day. Lenders, conveyancers, surveyors and HMRC all want a slice, and missing any of them out tells the buyer they can afford a property they actually cannot.

The calculator above lets you adjust each fee individually because they vary by lender and by region. Conveyancing in London averages 30% higher than the same work in Yorkshire. A new-build off-plan transaction with corporate vendor and shared ownership conveyancing can push the legal bill above £3,000.

Realistic 2026 fee benchmarks

• Mortgage arrangement (product) fee: £0 (fee-free deal) to £1,995 (lower rate, larger fee). Averages £999.
• Mortgage broker fee: £0 (lender-paid) to £495.
• Basic valuation: many lenders include free; outside of free deal £300–£600.
• HomeBuyers' Survey (RICS Level 2): £400–£700.
• Building Survey (RICS Level 3): £700–£1,500 — recommended for older or unusual properties.
• Conveyancing legal fees plus disbursements: £1,200–£2,400 freehold; £1,800–£3,000 leasehold.
• Local authority searches: £100–£250.
• Land Registry fee (£350,000 freehold): £135 (online) or £270 (postal).
• Bank transfer / TT fee: £20–£50.
• SDLT (£350,000 standard residential): £5,000.

£200,000 first-time buyer

£20,000 deposit + £0 SDLT (under £425k FTB threshold) + £1,500 conveyancing + £400 survey + £499 arrangement + £300 searches/reg = £22,699 cash. Loan £180,000 at 4.5%/25 → £1,001/month.

£500,000 family upgrade

£100,000 deposit + £12,500 SDLT + £2,200 conveyancing + £700 survey + £1,495 arrangement + £400 searches/reg = £117,295 cash. Loan £400,000 at 4.5%/25 → £2,224/month.

£900,000 leasehold flat London

£180,000 deposit + £33,750 SDLT + £3,200 conveyancing (leasehold premium) + £900 survey + £1,995 arrangement + £550 searches/reg = £220,395 cash. Loan £720,000 at 4.5%/25 → £4,003/month.

Common mistakes to avoid

• Forgetting the lender arrangement fee — it is sometimes added to the loan, but you can choose to pay upfront.
• Using the freehold legal fee for a leasehold purchase; leasehold work is usually £400–£600 more.
• Skipping the survey to save money — a £550 RICS Level 2 has saved buyers £20,000+ on hidden defects.
• Underestimating searches and Land Registry on higher-value freehold purchases — both scale with price.
• Using a 'free legal fees' lender deal without reading the small print — you may pay disbursements (≈£300–£500) anyway.

When to use this calculator

Run the calculator immediately after the offer is accepted, again after the survey if you need to renegotiate, and one final time the week before completion to confirm cash on completion. Buyers using gift money should add a buffer of £1,000+ for unexpected disbursements.

How this differs in Scotland, Wales and Northern Ireland

Conveyancing fees in Scotland are usually fixed-fee and lower than England (£900–£1,400 typical). Welsh transactions use Land Transaction Tax (different bands), and the Land Registry is replaced by Registers of Scotland or Land Registry of Northern Ireland depending on the country. New-build registration in Scotland is usually faster but lender fees and surveys mirror England closely.

When this calculator is and isn't the right tool

The Mortgage Calculator with Stamp Duty 2025/26 above is built for the most common UK 2025/26 scenarios in this tax area. It will be the right tool when your situation maps cleanly onto the inputs — single property or simple aggregation, standard HMRC rates and bands, and individual taxpayer (rather than complex trust or partnership structures). It is informational and does not replace tailored advice from a chartered tax adviser, especially for transactions above £500,000, cross-border situations, or where reliefs interact with each other. For year-end filings, always reconcile with HMRC's own free calculators on gov.uk before pressing submit on Self Assessment.

Closely related calculators

• Mortgage and Stamp Duty Calculator — useful when you need a different angle on the same UK property tax topic, especially if your situation involves multiple types of property income or disposal.
• Total Property Purchase Cost — useful when you need a different angle on the same UK property tax topic, especially if your situation involves multiple types of property income or disposal.
• Mortgage Stamp Duty 2025/26 — useful when you need a different angle on the same UK property tax topic, especially if your situation involves multiple types of property income or disposal.
• Mortgage Affordability — useful when you need a different angle on the same UK property tax topic, especially if your situation involves multiple types of property income or disposal.
• Stamp Duty Rates 2026 — useful when you need a different angle on the same UK property tax topic, especially if your situation involves multiple types of property income or disposal.

Glossary of UK property tax terms

SDLT

Stamp Duty Land Tax — the UK government tax on residential property purchases in England and Northern Ireland.

HRAD

Higher Rates for Additional Dwellings — the formal name for the 5% surcharge on second homes and BTL purchases.

SDLT1

The HMRC return form filed within 14 days of completion to declare and pay SDLT.

Sliced bands

SDLT is charged on slices of the price within each band, not on the whole price at the highest band.

Effective rate

Total SDLT divided by the purchase price, expressed as a percentage.

Section 24

The 2017 rule replacing full mortgage interest deduction with a 20% tax credit for individual residential landlords.

SA105

The Self Assessment supplementary form for UK property income.

Box 44

The SA105 box for residential property finance costs (mortgage interest).

Property allowance

£1,000 tax-free band for individual property income, claimable instead of expenses.

Rent-a-Room scheme

Separate £7,500 allowance for letting a furnished room in your main home.

Tax planning checklist

1. Confirm the figures input above match your actual position — purchase contract, mortgage offer or completion statement.
2. Cross-check the year (2025/26) — figures change every April. The tax year 2026/27 starts 6 April 2026.
3. Use HMRC's official calculator at gov.uk for the final filing figure; this calculator is informational.
4. Keep records for at least 6 years — HMRC's normal enquiry window. 21 years for fraud investigations.
5. Discuss any unusual transaction (joint purchase, gift, divorce settlement, trust) with a qualified tax adviser.
6. Submit your return online via Government Gateway — paper deadlines are earlier and penalties harsher.