Free Pro-Rata Share Calculator

Pro-rata share equals the tenant's leased square footage divided by the denominator (the building area used for allocation). A tenant leasing 5,000 SF in a 100,000 SF building has a 5% pro-rata share. The critical variable is the denominator: total GLA, occupied GLA, or leasable GLA can produce materially different allocations for the same tenant.

Total GLA uses the entire building footprint. Occupied GLA uses only leased space, increasing each tenant's share when vacancies exist. Leasable GLA excludes common areas and management offices. For a building with 10% vacancy, the difference between total and occupied GLA denominators can shift a tenant's share by 10-15%, translating to thousands of dollars annually.

When an anchor tenant is excluded from the CAM pool (common in retail leases), the denominator shrinks and every remaining tenant's pro-rata share increases. A 50,000 SF anchor exclusion in a 200,000 SF building means the remaining tenants split costs over 150,000 SF instead of 200,000 SF. That is a 33% increase in their individual share percentages.

Gross-up inflates variable expenses to a target occupancy threshold before applying pro-rata shares. Without gross-up, tenants in a 70% occupied building pay their share of understated variable costs. With gross-up to 95%, variable expenses are adjusted upward, and the grossed-up total is then divided by the chosen denominator. The interaction between gross-up and denominator choice can compound allocation differences significantly.

This typically happens when the denominator includes vacant space or excluded anchors. If you use total GLA as the denominator but only have 80% occupancy, tenant shares sum to 80%. If an anchor is excluded, tenant shares sum to the non-anchor percentage. Whether you gross up to cover the gap or absorb it as landlord vacancy cost depends on lease language.