Numbers you can trust
before you bid.
Four calculators, no signup, no paywall. Model the deal on your phone in the auction room — then let Legalpak's AI check the pack while you queue at the bar.
Before you raise the paddle
Max bid calculator
Work backwards from your target yield to the highest price you should pay at the hammer.
On the day + 28 days later
Auction deposit & completion cost
10% deposit due on the day, plus buyer's fee, SDLT, legals — your total true purchase cost.
Yield, cashflow, ROI
Buy-to-let calculator
Gross yield, net yield, monthly cashflow and cash-on-cash return — the full BTL model.
UK SDLT (2026 rates)
Stamp duty calculator
Standard + additional-property (5% surcharge) + first-time-buyer relief, band by band.
And when the numbers stack up…
Read the whole legal pack.
Before the hammer falls.
Legalpak's AI reads every clause of the pack, translates the legalese, and flags risks in a traffic-light report — in under a minute.
These calculators are for guidance only, not financial advice. UK SDLT rates verified February 2026 (effective April 2025). Always verify final figures with HMRC and your solicitor before completion.