How long will this project actually take?
Raw hour estimates rarely match reality once team availability, revisions, and client feedback delays are factored in. This calculator builds those in.
What it means
"Project timeline" here means the realistic number of calendar weeks a project will take, based on total estimated hours, how many people are working on it, their real weekly availability, and a buffer for the unexpected.
Why it matters
Quoting clients a bare-bones estimate with no buffer sets up missed deadlines and damaged trust the moment a revision round or feedback delay happens — which is nearly always.
Try it with your own numbers
Plan for about 5 weeks, including buffer
4 wks
Base timeline (no buffer)
4.8 wks
Realistic timeline (with buffer)
30 hrs/wk
Weekly team capacity
20%
Buffer applied
Recommendations
- Quote the buffered timeline, not the base estimate — buffer protects client trust when revisions or delays happen.
- Communicate a range (e.g. base to buffered weeks) rather than a single hard date.
- Revisit this estimate at each project milestone as real hours logged start to differ from the plan.
Suggested next steps
- See how project milestones and shared timelines look in a client-visible portal.
- Run the Team Cost Calculator to see what this timeline actually costs to deliver.
Relevant Sarion features
Keep work moving forward
Deadlines stay visible instead of living in someone's memory.
- Status tracking
- Due dates
- Task checklists
A branded space for your clients
Status-update emails go away almost entirely.
- Branded portal
- Comments
- Progress visibility
- Shareable access
What's typical
Typical recommended buffer
15-25% above the raw estimate
Realistic weekly availability per person
Often 50-70% of a 40-hour week once other work is accounted for
Client feedback turnaround
Frequently the single biggest source of timeline slippage
What actually moves this number
- Quote the buffered timeline to clients, not the raw base estimate — buffer protects trust when revisions or delays happen.
- Communicate a range rather than a single hard date so a slower feedback round doesn't break the commitment.
- Revisit the estimate at each project milestone as real hours logged start to differ from the plan.
Where this usually goes wrong
- Quoting the base estimate with no buffer at all.
- Assuming a team member has 100% of their week available for one project.
- Not accounting for client feedback turnaround time as part of the timeline itself.
Common questions
Why is my realistic timeline so much longer than the base estimate?
Buffer compounds with limited weekly availability — if your team only has a fraction of their week free for this project, base hours stretch out fast even before buffer is added.
What buffer percentage should I use?
15-25% is a reasonable starting point for most projects. Use a higher buffer for projects with more client dependencies or unclear scope, and a lower one for well-defined, repeatable work.
Does this account for dependencies between tasks?
No — this is a capacity-based estimate assuming hours can be distributed across the team. Highly sequential projects (one task blocking the next) may need a longer timeline than this shows.
Put these numbers to work
Sarion is where the client records, invoicing, and portal behind these numbers actually live.