Make the result useful
How to measure lease-expiration concentration in a rental portfolio
Lease-expiration concentration shows what share of active leases will roll in one selected month or period. A high result does not automatically mean trouble, but it highlights where renewal outreach, pricing review, and turnover capacity may be tested at the same time.
Use active lease counts on a consistent date and separate fixed-term expirations from month-to-month agreements. The goal is to make the workload visible early enough to offer renewals, stagger terms when appropriate, and plan vendor capacity.
The assumptions that move this result
Active leases
All current fixed-term leases in the portfolio on the selected reporting date.
Expiring leases
The subset ending in the selected month, quarter, or other stated period.
Reporting period
The exact month or range used for the count; keep it consistent across the portfolio.
Tenancy type
A note identifying month-to-month or other agreements that do not fit a fixed expiry count.
expiration concentration = leases expiring in the selected period / active leases
The output is the share of leases rolling together. It identifies timing exposure, not expected vacancy or renewal results.
Read the number in context
Portfolio example
Four fixed-term expirations out of 12 active leases produces a 33.3% concentration for that period.
Planning example
If eight of 20 leases end in August, start renewal and condition-review work early so potential turns do not all enter make-ready at once.
Month-to-month edge case
Month-to-month tenancies may create notice-driven exposure but should not be counted as a single fixed expiration without stating the method.
The calculator does not predict renewals, lawful notice requirements, market demand, resident decisions, or actual vacancy.
Before you act
• Export active lease dates from one source of record.
• Review renewal options before the relevant notice window.
• Model make-ready and marketing capacity for clustered expirations.
• Track the same concentration by month for the next 12 months.
Direct answer
Lease-expiration concentration equals the number of leases expiring in the selected period divided by all active leases on the same reporting date.
What concentration is too high?
There is no universal threshold. Compare the cluster with your leasing, maintenance, and cash-reserve capacity.
Should month-to-month tenancies be included?
Track them separately or state a consistent assumption, because they do not have the same fixed expiration date.
Does a high concentration mean I should change every lease term?
Not automatically. Consider resident preference, local requirements, and the operational reason for changing a term before proposing it.