The capacity model (simple on purpose)

The calculator converts your inputs into effective capacity using a step‑down method: gross hours → subtract time off → apply utilization → subtract meetings → apply buffer.

• Hours/day = Hours/week ÷ 5
• Gross capacity = Team × Hours/day × Workdays
• Net capacity = Gross − (Team × Time‑off days × Hours/day)
• After utilization = Net × Utilization%
• After meetings = After utilization × (1 − Meetings%)
• Effective capacity = After meetings × (1 − Buffer%)

• Load % = Demand ÷ Effective capacity
• Project slots = Effective capacity ÷ Avg hours per project
• Extra FTE ≈ (Demand − Effective capacity) ÷ Effective hours per person

What to do with the result

• If load is under 80%…

  You have slack. Use it for QA, documentation, sales, systems, or tackling technical debt.

• If load is 80–95%…

  This is a common “healthy” zone. You’re busy, but you still have room to absorb surprises.

• If load is above 100%…

  Something must give: scope, deadline, or staffing. Use the “Extra FTE” estimate to make the trade‑off explicit.

• If project slots feel low…

  That’s normal. Most teams are surprised by how much capacity meetings + rework consume. Reduce overhead first.

Capacity Planning Calculator: how it works (and how to use it to stop overbooking)

Capacity planning is the simple discipline of answering one question: how much “real work” can your team finish in a given period without burning out or dropping quality? The problem is that most teams plan with “calendar hours” (40 hours/week × people) while reality is “effective hours” after meetings, context switching, time off, and a safety buffer. That mismatch is exactly why projects slip, sprints feel chaotic, and freelancers end up working nights.

This calculator converts your team’s schedule into effective delivery capacity and compares it to your expected demand. It also estimates how many projects (or tasks) you can confidently take on, and how many additional full‑time equivalents (FTEs) you would need if demand exceeds capacity. Use it weekly if you run a services business, or monthly if you’re planning staffing, hiring, or launch timelines.

We start with your Gross Capacity — the raw working hours on the calendar:

• Hours per day = Hours per person per week ÷ 5
• Gross Capacity = Team size × Hours per day × Period workdays

Then we subtract planned time off. Time off is a “silent killer” because it often gets ignored until the week of delivery:

• Time Off Hours = Team size × Time off days × Hours per day
• Net Capacity = Gross Capacity − Time Off Hours

Next, we apply utilization. Utilization is the percentage of time that can be spent on deliverable work (client work, product build, execution). If you’re a freelancer, utilization might be 60–80% depending on admin and sales. If you’re a corporate team, it might be 40–70% depending on process, approvals, and interruptions:

• Utilized Hours = Net Capacity × (Utilization % ÷ 100)

Now we reduce utilization further with meeting/overhead. Even if you label time “billable” or “productive,” meetings and coordination eat focus. This slider captures recurring meetings, status updates, Slack pings, and unavoidable overhead:

• After Meetings = Utilized Hours × (1 − Meeting % ÷ 100)

Finally, we apply a buffer. A buffer is not laziness — it’s your risk management layer for bugs, rework, client feedback cycles, unexpected emergencies, and “it always takes longer than you think.” High‑quality teams plan with buffers:

• Effective Capacity = After Meetings × (1 − Buffer % ÷ 100)

That final number is the real headline: Effective Capacity. It’s what you can safely commit to without relying on heroics.

Demand is simply how many hours of work you expect during the period. If you’re planning a sprint, demand might be the estimated hours from your backlog. If you run an agency, demand might be hours sold in retainers plus any one‑off projects. We compute:

• Capacity Gap = Effective Capacity − Demand Hours

If the gap is positive, you have slack (good: room for QA, innovation, or sales). If negative, you’re overloaded (bad: you’ll slip, churn, or burn out). The calculator also shows Load %:

• Load % = Demand Hours ÷ Effective Capacity × 100

A healthy planning range is often 70–90% load. Above 100% load, you’re planning for failure unless you intentionally accept risk.

To make capacity feel concrete, we translate effective capacity into “project slots.” If your average project (or major deliverable) takes 40 hours, and you have 200 effective hours, you have about 5 project slots. The calculator uses:

• Project Slots = Effective Capacity ÷ Average hours per task/project

This helps freelancers and consulting teams instantly see whether they can accept another client, and helps product teams decide whether to add another major initiative this month.

If demand exceeds effective capacity, we estimate the additional headcount needed using your own efficiency assumptions. We compute how many effective hours a single person contributes in the selected period (after utilization, meetings, and buffer), then divide the shortage by that:

• Effective hours per person = Hours/day × Period workdays × Utilization × (1 − Meeting %) × (1 − Buffer %) − Time off adjustment
• Extra FTE needed = max(0, Demand − Effective Capacity) ÷ Effective hours per person

This output is best used as a conversation starter. If the calculator says “+0.8 FTE,” you can interpret that as: hire a part‑timer, reduce scope, push deadlines, or increase efficiency.

Example A — Freelance studio planning a month

You have 3 people. Each person works 35 hours/week. You expect 70% utilization (because some time is sales/admin). Meetings are 15%. You want a 10% buffer. Each person will take 1 day off this month. For a “Month” period (20 workdays), the calculator does:

• Hours/day = 35 ÷ 5 = 7
• Gross = 3 × 7 × 20 = 420 hours
• Time off = 3 × 1 × 7 = 21 hours → Net = 399
• Utilized = 399 × 0.70 = 279.3
• After meetings = 279.3 × 0.85 = 237.4
• After buffer = 237.4 × 0.90 = 213.7 effective hours

If demand is 240 hours, you’re overloaded by ~26 hours. That might be solved by removing a feature, renegotiating a deadline, or increasing utilization slightly (but be careful: utilization often has a ceiling).

Example B — Startup product team planning a sprint week

You have 6 engineers. Everyone is “40 hours/week,” but utilization is realistically 65% (support, reviews, planning). Meetings/overhead are 25% (standups + reviews + syncs). You want a 15% buffer because you’re shipping a risky feature. No time off this week. For a “Week” period (5 workdays):

• Hours/day = 40 ÷ 5 = 8
• Gross = 6 × 8 × 5 = 240
• Net = 240
• Utilized = 240 × 0.65 = 156
• After meetings = 156 × 0.75 = 117
• After buffer = 117 × 0.85 = 99.5 effective hours

If your sprint backlog is estimated at 120 hours, load = 120 ÷ 99.5 ≈ 121%. That’s the classic “we’ll just work harder” plan. A better move is to cut 20 hours of scope, or deliberately move lower‑priority tickets into the next sprint.

• Run it in public: in a weekly planning meeting, fill the sliders together and agree on utilization/meeting %. Alignment beats optimism.
• Track trends: save snapshots weekly. If your meeting % climbs, your capacity silently shrinks.
• Use “buffer” as a safety dial: big launches need higher buffers; steady-state maintenance can use smaller buffers.
• Don’t game utilization: increasing utilization usually increases churn. The best improvement is often lowering meetings or clarifying scope.
• Make demand explicit: if demand hours are unknown, estimate with ranges and plan for the higher number.

• What utilization % should I use?

  Freelancers often land around 60–85% depending on admin/sales. Teams in larger orgs can be 40–70% depending on coordination and interruptions. If you’re unsure, start at 70% for small teams and adjust after a few weeks of reality checks.

• Is meeting % double-counting utilization?

  It can be if you already “baked meetings” into utilization. To avoid confusion: treat utilization as “work that could be deliverable” and meeting % as “focus tax on that deliverable work.” If you prefer a simpler model, set meeting % to 0 and lower utilization instead.

• Why include a buffer?

  Because estimation is uncertain. Buffers protect quality and reduce deadline drama. If you never need a buffer, you’re probably underestimating rework or relying on overtime without naming it.

• What does “Average hours per task/project” mean?

  It’s your typical effort per major deliverable. For agencies it could be “average project.” For product teams it might be “epic” or “feature.” Use a number that makes planning tangible.

• Can I plan for contractors or part-time help?

  Yes. Convert them to FTE. For example, a 20‑hour/week contractor is ~0.5 FTE compared to a 40‑hour baseline. Enter 0.5 increments in team size (this calculator supports decimals).

• Is this a perfect model?

  No — it’s intentionally simple. The goal is to make hidden capacity assumptions visible so you can have better decisions about scope, staffing, and timelines.

• Planning at 100% load: If every hour is booked, there is no room for bugs, client feedback, sick days, or context switching. Fix: plan at 80–90% load, and treat the remaining 10–20% as “reality.”
• Ignoring approvals and review cycles: Capacity is not just “build time.” Reviews, QA, stakeholder sign‑off, and revisions are real work. Fix: include them in demand hours or raise meeting/overhead.
• Assuming all team members are identical: Seniors often mentor, juniors need support, and specialists become bottlenecks. Fix: use team size as effective FTE (e.g., 4 people might be 3.2 effective FTE) until you have a more granular model.
• Underestimating handoffs: The more handoffs you have, the more coordination tax you pay. Fix: reduce meeting %, simplify ownership, or build “pods” around outcomes.
• Overusing buffers: A buffer is not a substitute for unclear scope. Fix: if you need 30% buffer every time, revisit estimation and definition of done.

• Set the period (Week or Month) and confirm planned time off.
• Agree on utilization and meeting % as a team (don’t guess privately).
• Estimate demand hours for committed work only (wishlist items go in a separate bucket).
• Check load %. If it’s > 100%, cut scope, move work, or add help — before execution starts.
• Save the snapshot and compare next week. Capacity planning becomes powerful when it becomes a habit.

Reminder: this calculator is an operational planning aid. For high‑stakes commitments, pair it with project breakdowns, risk registers, and stakeholder alignment.

Use responsibly

Capacity planning is an approximation. Treat the output as a decision aid, not a guarantee. For big commitments, pair this with detailed scoping and clear “definition of done.”

• Estimate demand honestly (include reviews, revisions, support).
• Plan for a buffer (especially during launches).
• Re-check weekly and adjust scope early.