Lease Extension Calculator
Whether you're a leaseholder looking to maintain or increase your property value or a landlord planning future tenancy arrangements, knowing your new lease term after an extension is essential. The Lease Extension Calculator provides a quick and accurate way to calculate your updated lease length.
Lease extensions are common in both residential and commercial real estate. In the UK especially, properties with leases below 80 years can drop in value and attract higher premiums for extension. This tool helps visualize how much longer your lease will run after adding an extension term.
Formula
The formula for a lease extension is very simple:
New Lease Term = Current Years Remaining + Years to Extend
For example, if your current lease has 65 years left and you’re granted a 90-year statutory extension, the new lease term will be:
65 + 90 = 155 years
This provides a quick and clear understanding of your updated lease length post-extension.
How to Use the Calculator
- Enter the number of years currently remaining on your lease.
- Enter the number of years you plan to extend it by (e.g., 90 years for statutory lease extensions in the UK).
- Click Calculate to instantly view your new total lease term in years.
Example
Let’s say your flat has a lease with 72 years remaining. You apply for a statutory lease extension under UK leasehold law, which grants an additional 90 years.
- New Lease Term = 72 + 90 = 162 years
This shows the new lease expiry point and helps you evaluate property value and financial planning.
Why It’s Important
- Preserve or increase property value – Longer leases are more valuable and attractive to buyers.
- Avoid marriage value costs – Leases under 80 years attract an additional cost during extension.
- Simplify financing – Banks are more willing to lend on properties with longer leases.
- Meet legal requirements – Certain property purchases or conversions require a minimum lease term.
FAQs
1. What is a lease extension?
A lease extension adds additional years to your current lease, increasing the total term.
2. Who can apply for a lease extension?
In the UK, leaseholders who have owned the property for at least 2 years can apply.
3. What is the standard extension period?
In the UK, a statutory extension grants 90 additional years on top of the current lease.
4. What is the 80-year rule?
If your lease has fewer than 80 years remaining, you may be liable to pay marriage value, which increases the cost of extension.
5. How do I find how many years are left on my lease?
Check your lease contract or your title register (from the Land Registry in the UK).
6. Does the calculator work for commercial leases?
Yes. Just enter your current lease and extension years to get the new total term.
7. Can I extend a lease multiple times?
Yes, though the costs and rules may differ depending on whether the lease is residential or commercial.
8. Is ground rent affected by a lease extension?
Under UK law, a statutory lease extension reduces ground rent to a peppercorn (effectively £0).
9. How long does a lease extension take?
It can take anywhere from 2 to 12 months, depending on whether it’s a negotiated or statutory process.
10. Is lease extension necessary to sell a flat?
Not always, but selling is much easier (and more profitable) when the lease has more than 80–90 years remaining.
11. What if I don’t extend my lease?
The lease length will continue to decrease, reducing the property’s market value and your financing options.
12. Do I need to hire a solicitor or surveyor?
Yes. For statutory extensions, you’ll need both legal and valuation advice.
13. What happens after the lease expires?
You may lose legal ownership of the property unless other arrangements are made.
14. Does lease extension affect my mortgage?
Yes. Most mortgage lenders require a lease to have at least 70–80 years remaining.
15. What’s the difference between lease renewal and extension?
Renewal typically refers to starting a new lease. Extension adds years to the current one.
16. Can the calculator show the new expiration year?
This version shows years only. Let me know if you’d like a date-based version!
17. Can landlords use this tool?
Yes. It helps landlords and freeholders assess the updated lease terms for financial planning.
18. Can the lease be extended forever?
Legally, there’s no maximum, but extremely long leases (e.g., 999 years) are often considered virtual freehold.
19. Is lease extension the same in every country?
No. Lease extension rules vary. This calculator provides a simple estimate for all systems.
20. Will extending a lease always increase property value?
Yes — especially for leases under 90 years. Longer leases are far more marketable.
Conclusion
Whether you're a leaseholder planning to secure your property’s future or a landlord navigating renewal terms, the Lease Extension Calculator is a powerful yet simple tool. By clearly showing how many total years you'll have post-extension, it removes confusion and helps with decision-making, valuation, and negotiation.