How to Calculate Weighted Average Lease Term (WALT)

Weighted Average Lease Term (WALT) measures how much of a property’s or portfolio’s leased square footage is locked in versus exposed to rollover. It weights by area, not lease count. Asset managers use WALT to size rollover risk. Lenders use it to underwrite income durability. Getting the calculation right, and reading it correctly, takes more than averaging the numbers on a rent roll.

What Weighted Average Lease Term Tells You

Weighted Average Lease Term answers one question: how much leased area rolls, and when. A property with two leases expiring at the same time can carry very different risk. It depends on whether one lease covers 5,000 SF and the other covers 95,000 SF. WALT accounts for that. It weights each lease’s remaining term by its share of total area, not by treating every lease as equally important.

The metric feeds directly into rollover-risk analysis, debt underwriting, and hold-period planning. A short WALT on a portfolio with rents below market is a different story than a short WALT on a portfolio already priced at market. That distinction only shows up once you pair WALT with mark-to-market data, which we cover in Step 5.

This guide walks through the calculation step by step, then shows how to benchmark the result against CompStak lease data.

Step 1: Build the Lease Roster

Start with every active lease at the property or in the portfolio, including suite number, tenant, square footage, lease start date, and lease expiration date. Exclude vacant space; WALT measures leased area only, not gross leasable area.

Pull remaining term, not original term. A 10-year lease signed five years ago has five years of remaining term left. That’s the number that belongs in the calculation.

Step 2: Calculate Remaining Lease Term for Each Lease

Subtract the current date from each lease’s expiration date to get remaining term in months. Use months, not years, for precision, since most commercial leases don’t expire on clean annual boundaries.

If a lease has multiple renewal options, use the contractual term through the next firm expiration date only. Options that haven’t been exercised don’t belong in the base WALT calculation. Some analysts run a separate WALT assuming options are exercised, to stress-test the downside case. Always label that as a distinct scenario.

Step 3: Weight Each Lease by Square Footage

Multiply each lease’s remaining term (in months) by its square footage. This produces a weighted value for each lease that reflects both how long it runs and how much space it occupies.

Square footage is the standard weighting convention. WALT is meant to capture physical rollover exposure: how much of the building comes back to the landlord, and when. A rent-weighted version exists and is useful for income-exposure analysis. It answers a different question, though, and analysts should never blend it with the SF-weighted figure in the same reported number.

Step 4: Sum and Divide to Get WALT

Add up the weighted values from Step 3, then divide by total leased square footage. That quotient is the WALT.

Here’s a worked example using a hypothetical three-tenant building for illustration:

Lease	Square Footage	Remaining Term (months)	Weighted Value (SF × months)
Lease A	50,000 SF	84	4,200,000
Lease B	20,000 SF	36	720,000
Lease C	30,000 SF	120	3,600,000
Total	100,000 SF	—	8,520,000

WALT = 8,520,000 ÷ 100,000 SF = 85.2 months, or roughly 7.1 years.

Notice that Lease A and Lease C, the two largest tenants, pull the result up despite Lease B’s shorter term. That’s the point of weighting by area. A small tenant’s near-term expiration doesn’t distort the picture the way it would in a simple average.

Key Takeaway: WALT is the sum of (square footage × remaining term) across every lease, divided by total leased square footage. Weighting by area, not lease count, is what separates WALT from an average lease term.

Step 5: Benchmark the Result

A WALT number means little in isolation. Benchmark it against peer portfolios and against the property’s expiration schedule. Then check it against where market rents sit relative to in-place rents.

CompStak’s portfolio-level data shows how WALT varies by ownership cohort. Nareit Office landlords carry a WALT of 69.9 months versus 63.2 months for all other office owners, per CompStak’s Portfolio comparison: FTSE Nareit Office index owners vs all other office owners. In industrial, Nareit Industrial owners run a WALT of 51.8 months against 44.6 months for all other owners, per CompStak’s Portfolio series: FTSE Nareit Industrial vs all other industrial owners.

Sector	Landlord Cohort	WALT (months)
Office	Nareit Office landlords	69.9
Office	All other office owners	63.2
Industrial	Nareit Industrial landlords	51.8
Industrial	All other industrial owners	44.6

Source: CompStak’s Portfolio comparison: FTSE Nareit Office index owners vs all other office owners and Portfolio series: FTSE Nareit Industrial vs all other industrial owners. Data as of early 2026.

Pair WALT with the expiration wall. More than 32% of all office leases are set to expire between Q2 2026 and year-end 2028, and roughly 31% of leased industrial SF is scheduled to expire in that same Q3 2026 to Q2 2028 window, per CompStak’s 2025 Biannual Office Market Report — Part Three and 2026 Biannual Industrial Market Overview — Part Four. A shorter WALT sitting on top of that wall means more of the portfolio is exposed to whatever rents do next.

That’s why analysts need to read WALT alongside where rents are heading. As of May 2026, the national Columbia CompStak Rent Index (CCRI) shows office rents up 7.4% year over year and industrial up 3.9%. A short WALT in a market with rising rents is an opportunity to mark leases to market sooner. A short WALT in a softening market is the opposite: exposure without upside.

Step 6: Segment WALT by Asset Class and Market

A single building-level WALT can hide divergence between asset classes. Lease term itself has moved differently by class over the past several years. Class B/C office lease terms remain 8.5% below the Q4 2019 baseline, a gap that has held for 24 consecutive quarters, while the rest of Class A has surpassed pre-COVID lease-term levels for six straight quarters, per CompStak’s 2025 Biannual Office Market Report — Part Three. Prime Class A, by contrast, has exceeded its 2019 lease-term baseline in only one of the past 24 quarters.

Industrial shows a similar size-based split. Leases of 200,000 SF or more averaged 80.2 months in Q1 2026, close to the 80.6-month pre-COVID baseline, while sub-200,000 SF leases settled at 59.7 months, per CompStak’s 2026 Biannual Industrial Market Overview — Part Four. Running WALT separately by size band or asset class surfaces that gap instead of averaging it away.

Common Pitfalls When Calculating WALT

Weighting by lease count instead of square footage. Don’t treat a five-lease, five-tenant floor, with one anchor and four small suites, as if each lease carries equal weight.

Using original term instead of remaining term. WALT measures what’s left, not what was signed.

Including unexercised renewal options in the base case. Options inflate WALT and understate rollover exposure unless run as a separate scenario.

Mixing units. Keep the calculation in months throughout, and convert to years only in the final reported figure.

Reading WALT without mark-to-market context. The same WALT number carries opposite implications depending on whether in-place rents sit above or below current market rents.

Blending SF-weighted and rent-weighted WALT. They answer different questions. Report them separately.

Tracking remaining term across a rent roll accurately depends on having verified lease data to begin with. CompStak’s Portfolios product consolidates lease-level data, including remaining term and square footage, across a holding so teams can monitor WALT and rollover exposure as leases move through their term. Get started with CompStak to see how verified lease comps support portfolio-level rollover analysis.