Understanding Schedule Delay Days Rate
How we calculate. Delay % = total delay days ÷ planned workdays × 100. See our methodology and accuracy policy .
Real-world scenario: A typical Schedule Delay Days Rate case uses delay days 9 and planned workdays 60. Enter the same figures below to reproduce the worked path.
What is Schedule Delay Days Rate?
A calendar delay KPI broader than weather-only delay %. Not SPI/SV—those are earned-value tools on the Professional hub.
- All-cause delay days (or labeled subset)
- Same workday basis
- Cross-link weather delay % for weather-only
The Formula
Worked Example
Common Use Cases
- Schedule narrative: delay intensity
- Owner reports: lost workdays
- Risk reviews: delay vs plan
Pro Tips
- Code delay causes
- Avoid double-counting concurrent delays
- Use SPI for EV schedule performance
| Scenario | When to use |
|---|---|
| Percent of a number | Finding a part of a whole (tax, tip, score) |
| Percent change | Comparing old vs new values |
Limitations: Schedule Delay Days Rate results are educational construction planning aids—not engineering, safety, legal, or cost-estimating advice. Confirm definitions with your project controls, safety, and contract documents. For earned-value SPI/CPI see the Professional hub.
Common mistakes
- Swapping part and whole: The denominator must be the full total, not a subset.
- Rounding too early: Carry extra decimal places through multi-step work before rounding the final percent.
- Mixing percent and decimal forms: Enter rates in the format the calculator labels expect.
The worked example for schedule delay days rate was verified with the calculator form on this page—enter the same values to confirm the result.
When to use this calculator
- Use this page when your wording matches schedule delay days rate and the form labels on screen.
- Use percent of a number for “what is X% of Y?” problems.
- Use number is what percent when you know part and whole and need the percent.
Still unsure about schedule delay days rate? Start with the quick answer above, then open the linked calculator that matches your wording.
❓ Frequently Asked Questions
How do I use this schedule delay days rate calculator?
For schedule delay days rate, enter the values labeled on the form, then press Calculate. Compare the result to the worked example on this page.
What formula does this page use?
See the quick answer and formula box above for schedule delay days rate—the same percentage calculator expression is applied to your inputs.
What if my result looks wrong?
When checking schedule delay days rate, re-check part vs whole (or rate vs base), rounding, and whether percents were entered as 25 rather than 0.25 when the form expects percents.
Authoritative References
For construction project controls and safety rate concepts, consult: