Estimate a lease extension premium using a practical UK-style valuation model with ground rent loss, reversion, and marriage value.
Enter your lease details to estimate the extension premium…
The estimate combines ground rent loss, reversionary loss, and marriage value when applicable.
It is a planning tool only and should not replace a valuation by a qualified leasehold surveyor or solicitor.
Important notes:
Marriage value usually becomes relevant when the lease has under 80 years remaining.
Actual premiums can vary based on market value, negotiations, and legal assumptions.
This calculator is intended for quick estimates and user understanding.
What is a Lease Extension Calculator?
A Lease Extension Calculator is an online tool designed to estimate the cost of extending a property lease. It’s commonly used in markets like the UK, where leasehold ownership is widespread.
Instead of complicated legal formulas, the calculator simplifies things by asking for a few key inputs and then giving you an approximate cost. Think of it like a financial preview before making a serious property decision.
Why Lease Extension Matters
Leasehold properties lose value as the lease term gets shorter.
👉 Once your lease drops below 80 years, things get expensive due to something called Marriage Value.
This is the most critical factor. The fewer years left, the higher the cost.
4. Yield / Capitalization Rate
Used to calculate the present value of future ground rent.
5. Marriage Value (if under 80 years)
This adds a significant extra cost shared with the freeholder.
Example (Simple Breakdown)
Let’s say:
Property Value: $300,000
Ground Rent: $200/year
Remaining Lease: 75 years
Since the lease is below 80 years, marriage value applies, increasing the extension cost significantly.
👉 A calculator might estimate:
Lease extension cost: $15,000 – $25,000 (approx.)
A Lease Extension Calculator is a smart first step if you own or plan to buy a leasehold property. It removes confusion, gives clarity, and helps you make informed financial decisions.
