How does the delivery date calculator work?
An estimate describes how much work a task requires, but it does not yet say when that work will finish. The calculator turns estimated effort into a date using the start date, realistic daily capacity, working days, public holidays in the selected country and a planning buffer. Forty hours therefore do not automatically mean five calendar days: at six project hours per day, the work needs about seven working days before weekends and holidays are placed in the calendar.
From an hourly estimate to a specific date
First divide the estimated effort by the number of hours that can realistically be spent on the project each day. Round the result up to complete working days, then move through the calendar while skipping non-working days.
estimated effort ÷ real daily capacity = required working days
40 hours ÷ 6 hours per day = 6.67, so plan 7 working days
Why not assume eight project hours every day?
An eight-hour working day rarely provides eight uninterrupted hours for one project. Meetings, code review, communication, support work and context switching reduce real project capacity. Seven or eight hours may suit focused work, five or six may be more realistic in a mixed day, and parallel responsibilities can reduce availability to two or three hours.
Weekends and public holidays matter
A delivery date should reflect the days on which work can actually happen. The calculator skips weekends and the public holidays supported for the selected country. This matters especially in international projects, where the team and client may follow different calendars and a multi-week delivery window can contain several non-working days.
Earliest delivery and recommended delivery
The earliest date follows directly from estimated effort, capacity and the working calendar. The recommended date adds the selected planning buffer for small delays, context switching and unexpected fixes. Neither date is a guarantee, but showing both makes the baseline and the safer planning assumption explicit.
When should you use the calculator?
Use it when you already have an approximate estimate in hours or working days and need to answer: “When can we realistically deliver this?” It is useful before communicating a date to a client, planning a task, sprint or project stage, and checking whether an expected deadline is feasible.
If you do not yet have an effort estimate, start with the Quick Task Estimate.
The result is a planning aid. It cannot account for team leave, unplanned absence, scope changes, delayed decisions, external dependencies or downtime that is not represented in the inputs.
Common questions
How do I calculate a project delivery date?
Divide the estimated effort by realistic daily project capacity, round up to complete working days and place those days in the calendar while skipping weekends and public holidays. Add a sensible buffer when the date will be used as a commitment.
Does the calculator include weekends and public holidays?
Yes. It calculates in working days and excludes the public holidays supported for the selected country.
How many hours per day should I enter?
Enter the time that can genuinely be spent on this project, not the full length of the working day. If two hours are normally used by meetings and other duties, six hours may be a more realistic value than eight.
Why add a planning buffer?
A buffer leaves room for limited variation such as small fixes, context switching or short communication delays. It should not replace analysis of large, known risks.
What is the difference between the earliest and recommended dates?
The earliest date follows directly from effort and capacity. The recommended date includes the selected buffer and is usually safer for planning and communication.