Leasehold Property law. Personally delivered.
Leasehold Property law. Personally delivered.
Calculators
An indication of the premium payable to your landlord for a statutory 90-year lease extension with the ground rent reduced to a peppercorn — the extension most leaseholders of flats are entitled to claim. For the full statutory process and our fees, see Lease Extensions.
The value of your flat with a long lease. Roughly what it would be worth with, say, 999 years remaining and no ground rent. Recent sale prices of similar flats nearby are a reasonable guide.
The unexpired term of your lease. The number of years left to run, taken from the lease itself or your title register.
The current ground rent. The annual figure you pay now. Where the rent doubles or rises on a pattern rather than staying fixed, this calculator's straight-line assumption will understate the premium — ask us and we will run the figures properly.
Calculated under Schedule 13 to the Leasehold Reform, Housing and Urban Development Act 1993
Indicative premium range
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Relativity is derived from a graduated relativity curve applying conventional assumptions. This is a simplified, non-binding estimate for guidance only — it does not account for onerous or unusual ground rent terms, development value, or comparable evidence specific to your building. For a figure you can rely on in negotiation with your landlord, get a formal valuation from an RICS Registered Valuer, such as our colleagues at Blakes Chartered Surveyors.
Don’t know your lease length?
The calculator above needs your unexpired term. If you do not have it to hand, the Leasehold Advisory Service — the government-funded advice body — offers a free lease length check for flats and houses in England and Wales. You will need the property address and an email address.
It saves buying a Land Registry title register, which costs a few pounds and takes longer. Once you have the term, come back and enter it above.
A note on estimates
LEASE also provides a premium estimate. Like ours, it is indicative only and should not be used as a basis for negotiation. Where a notice has been served or terms are being agreed, a formal valuation from an RICS Registered Valuer is what the other side will expect.
The Leasehold Advisory Service is an independent body funded by the Ministry of Housing, Communities and Local Government. Arcadia Law is not affiliated with LEASE and is not responsible for the content of external sites.
It applies conventional assumptions to three numbers. A formal valuation considers your actual lease, your actual building and the actual evidence, and matters most in these situations:
Rents that double at short intervals, or are linked to RPI or a proportion of value, behave very differently from a fixed rent and need their own calculation.
Shared ownership, leases with unusual rights or restrictions, and houses rather than flats all sit outside the statutory formula this tool assumes.
The relativity percentage is the single most contested figure in most claims. This tool applies a graduated curve; a valuer selects a figure for your specific building and the evidence available.
Where a building has potential for further development, an additional element can be payable that this calculator does not attempt to estimate.
Send us the lease, or simply the address and the number of years remaining, and we will tell you where you stand and what a claim is likely to cost. The first conversation is at no cost.
This calculator gives an indicative, non-binding estimate only and is not a valuation. Figures exclude the landlord's costs, your own legal and valuation fees, and disbursements. Arcadia Law Ltd is a private limited company registered in England and Wales, company number 10043933, registered office 15 Approach Road, London SW20 8BA. Authorised and regulated by the Solicitors Regulation Authority, SRA number 629605. © Arcadia Law Ltd 2026.
