A deadline from a start date and duration.
Tool · Last updated May 14, 2026
Project Deadline Calculator
Useful for project planning, quotes, and delivery timelines.
This is a simple calendar deadline, not a business-day deadline.
Quotes, project plans, and delivery timelines.
This is calendar-day math, not business-day math.
Result
Run the tool to see the answer here.
Quick take
Turn a start date and duration into a deadline.
How it works
Three quick actions, no wall of instructions.
Set the start date
Choose when the project begins.
Add the duration
Enter the number of calendar days.
Verify the policy
Check weekends and holidays separately if needed.
Sample input
Sample output
Deadline: 2026-05-23
Gotchas
Confusing calendar days with business days.
Assuming holiday rules are included automatically.
Forgetting that your delivery policy may need a separate buffer.
Quick answers
Short answers for the edge cases people usually ask about.
What if the date is in the past?
It switches to an elapsed-time check instead of pretending the event is still ahead.
Should I set a time zone?
Yes for anything time-sensitive.
What should I confirm before using it?
Weekend or holiday rules if the deadline is strict.