FullCalculator

Project Timeline Calculator

Project Duration Estimate

Estimate project duration from total effort and team size

hours
days
%

Effort Estimator

Estimate total effort from number of tasks

hours

Formula

Duration = Total Effort / (Team Size x Hours per Day) x (1 + Buffer%) | Effort = Tasks x Avg Hours x Complexity

Frequently Asked Questions

How much buffer should I add to a project timeline?
A common rule of thumb is 15-25% buffer for well-understood projects. For projects with significant unknowns, use 30-50%. The buffer accounts for unexpected issues, scope changes, meetings, and context-switching overhead.
What are productive hours per day?
Most knowledge workers are productive for 5-6 hours in an 8-hour workday. The rest is spent on meetings, email, breaks, and context switching. Using 6 hours is a realistic estimate for planning.

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