Bidding Increment Calculator
See what going above your target price costs in extra deposit, extra monthly payment, extra interest over the term and extra transfer tax.
💼 Are you a real estate agent or broker? Send this calculator to your buyers on your own branded listing page — every enquiry comes straight to your WhatsApp. Create free agent page →In a competitive negotiation the next increment always feels small. Spread across a mortgage term it is not, and it also demands more deposit today and more transfer tax at completion — three separate costs from one decision made under pressure.
Seeing all three before the negotiation starts is what makes a walk-away price hold when the agent calls back.
Where the extra goes
Part of any increase is borrowed and part comes from your own deposit, in the same proportion as your loan-to-value. The borrowed part is priced over the mortgage term; the deposit part is cash today; and transfer tax is charged on the increase at your marginal rate.
Worked example
Going from 400,000 to 412,000 is 12,000 more. At 80% loan-to-value, 9,600 is borrowed and 2,400 comes from your deposit. At 6.5% over 25 years the borrowed part adds about 65 a month — 19,446 across the term — and transfer tax on the extra at 5% is a further 600.
Decide the ceiling before the call
Increments feel small individually and compound quickly. Writing down a maximum, with this number beside it, is what turns a walk-away price into something you can actually act on when the agent says there is another offer.
Turn a calculation into an enquiry
Buyers who run these numbers are ready to talk. Give every listing its own page with your photo, phone and WhatsApp on it — leads land straight on your phone.
Create your free property pageFrequently asked questions
Is a small increase really significant?
Over twenty-five years, yes. Twelve thousand extra costs nearly twenty thousand in payments plus the deposit and the tax. The monthly figure is what makes it feel trivial and the term figure is what makes it real.
Should I ever go above my walk-away price?
Only after recalculating, never in the moment. If the property is genuinely worth more to you than you first thought, the right response is a new number worked out calmly, not an increment agreed on the phone.
Does bidding higher affect the mortgage?
It can. A higher price with the same deposit raises the loan-to-value, which may push you into a worse rate band. Check whether the increase crosses a threshold before agreeing it.