Calculator inputs
All hours are per person, then multiplied by team size.
Formula used
The calculator converts your schedule into capacity, then subtracts planned deductions.
Core equations
Scheduled Hours = (Hours/Day × Days/Week × Weeks) + Overtime
Time Off Hours = (PTO + Sick + Holidays + Other Leave) × Hours/Day
Capacity Before Buffer = Scheduled − Time Off − Overhead
Buffer Hours = Capacity Before Buffer × Buffer% or Fixed Buffer Hours
Available Hours = max(0, Capacity Before Buffer − Buffer)
Billable Target = Available × Utilization%
Remaining Billable = max(0, Billable Target − Committed)
Team size multiplies all per-person hour totals.
Tip: Use a higher buffer when work is uncertain or interrupt-driven.
How to use this calculator
- Pick a period and confirm weeks in that period.
- Enter hours per day, days per week, and overtime.
- Add time off days for vacations, holidays, and leave.
- Enter overhead hours like meetings and administration.
- Choose a safety buffer and a utilization target.
- Click Calculate, then download CSV or PDF if needed.
Example data
A simple example to validate your inputs.
| Item | Example value | Notes |
|---|---|---|
| Period | Monthly | 4.33 weeks typical. |
| Hours per day | 8 | Standard workday. |
| Days per week | 5 | Monday to Friday. |
| PTO days | 2 | Vacation within the month. |
| Holidays | 1 | One public holiday. |
| Meetings | 12 hours | Recurring syncs and client calls. |
| Admin | 6 hours | Email, updates, and reporting. |
| Buffer | 10% | Protects against overruns. |
| Utilization target | 80% | Billable portion of available hours. |
What you should expect
- Scheduled hours near 173.2 for one person (8×5×4.33).
- Time off subtracts 24 hours (3 days × 8).
- Overhead subtracts 18 hours (meetings + admin).
- Buffer subtracts about 13.1 hours (10% of capacity).
- Billable target becomes roughly 94.4 hours at 80%.