Flat Extend Lease

Lease Extension Calculator

Years left on lease:
years months
Ground Rent (average):
per annum
Property Value (if extended)?
Deferment Rate (advanced users only)
  • Lower £ 62,834

    This is the lowest you should expect to pay for the premium.

  • Average £ 65,612

    What you should expect to pay for the premium.

  • Upper £ 68,350

    This is the highest you should expect to pay for the premium.

Lease Extension Calculator Information

The above figures should give you a reasonably accurate guideline to the likely premium that a Leasehold Valuation Tribunal would calculate using statutory methods. Online lease extension calculators will only work for fixed ground rents. If you have a variable ground rent, see doubling ground rent leases.

How is your lease extension cost calculated?


A complex algorithm is used to derive the estimated premium in line with the rules set out by statute, in particular Schedule 13 of the Leasehold Reform, Housing and Urban Development Act 1993. Modern case law decisions influence this algorithm, and we constantly monitor these decisions and tweak our methods accordingly. You may be interested to know that we are currently using the following variables:


Anyone considering extending their lease should obtain a professional Lease Extension Valuation report to assist with negotiations. This report is critical for any person wanting to negotiate the premium.



How to agree on a premium

Freeholders and leaseholders negotiate a premium based on their own valuations. Leaseholders should present their own calculations to the freeholder in a professional report with the aim of negotiating a lower premium. In fact, freeholders expect leaseholders to negotiate. We strongly recommend that you appoint a professional to deal with this aspect. Appoint a solicitor specializing in lease extensions at the very outset; a good solicitor should be able to analyze your valuation report and negotiate on your behalf to achieve the lowest possible premium. See our section on choosing a solicitor.




About our lease extension calculator

Our results reflect an extremely close approximation of the true cost of extending your lease in accordance with the rules, common law cases, and statutory requirements of a valuation. Our calculator adheres to these rules entirely, providing extremely accurate results; however, it does not substitute the need for a professional valuation report. Online estimates do not take into account rising ground rents, which can have a substantial impact on the valuation. It is common for residential leases to have ground rent reviews every 25 or 33 years (either as a fixed stepped amount, doubling, or even in line with RPI). We highly recommend that you instruct a solicitor who fully understands the valuation process and is able to negotiate on your behalf.

Disclaimer: We ask our users to not rely on our results; they are provided for guidance only.