Schedule Slippage Calculator

Schedule slips compound cost. This calculator quantifies total delay impact.

Planned duration (days)

Actual duration (days)

Daily carry

Daily lost revenue

Total slippage cost

$265,000

Slippage days

Slippage %

20.83%

How the math works

Slippage cost = slippage days × (daily carry + daily lost revenue).

Lost revenue after stabilization date is often overlooked. An 8-week delay on a 200-unit lease-up = $300-600k in lost rent plus carry. Track both dimensions.

How to Use

Enter planned duration.
Enter actual (projected) duration.
Enter daily carrying cost.
Enter daily lost revenue.
Read total slippage cost.

Frequently Asked Questions

Slippage sources?

Weather (10-20%), subcontractor delays, permit issues, scope additions, material delivery, labor availability, design changes. Track each cause; reduce recurring ones.

Typical slippage?

5-15% slippage is normal on commercial projects. 15-30% signals management or design issue. Over 30% often means project restart or major restructuring.

Mitigation?

Weekly schedule reviews with trade leads. Critical path analysis. Accelerated scheduling for milestone recovery. Per-day liquidated damages in contracts — even uncollected, they focus contractor attention.

How often should I rerun this?

Rerun this calculator whenever inputs change materially — new rent roll data, rate moves, loan balance updates, or quarterly operating data. For active deals, monthly refresh is typical. For stabilized assets under monitoring, quarterly is fine. Treat the output as a decision tool, not a one-time answer — market conditions evolve and so should your analysis.