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Fractional Executive Billable Capacity Estimator

The Fractional Executive Billable Capacity Estimator converts a working schedule into realistic client-facing capacity. It starts with the hours you expect to work each week and the number of working weeks in the year, then removes the share reserved for leadership administration, business development, proposals, travel, internal planning, and other non-billable work.

This is useful when a fractional CFO, COO, CMO, CTO, or other executive is deciding how many retainers or projects can fit into a year without assuming every working hour is sellable. The annual estimate can be compared with existing client commitments, while the monthly and weekly figures help with pipeline planning and workload checks. It is a capacity estimate, not a guarantee of demand or collected revenue.

Capacity assumptions

hours
weeks
%
Result
—
estimated billable hours per year
Gross working hours—
Billable hours per month—
Billable hours per working week—

1. Enter your weekly work limit
Use the total hours you are willing to work across client delivery and your own practice.

2. Set working weeks
Exclude planned vacation, holidays, and other full weeks you do not expect to work.

3. Estimate non-billable time
Include selling, administration, bookkeeping, networking, preparation, and internal work that cannot be invoiced.

4. Review billable capacity
Use the annual figure for contract planning and the monthly or weekly figures to compare with current commitments.

Formula:

Annual billable hours = Hours per week × Working weeks × (1 − Non-billable % ÷ 100)

Gross working hours are hours per week multiplied by working weeks. Monthly billable hours divide the annual estimate by 12. Billable hours per working week divide annual billable hours by working weeks.

What the result means

The main result is the maximum estimated number of hours available for client billing under the schedule and non-billable assumption you entered.

Actual capacity can be lower when client work is uneven, meetings overrun, or unplanned business-development and administrative work increases.

Given: 38 hours per week, 46 working weeks, and 28% non-billable time.

Calculation: Gross hours = 38 × 46 = 1,748 hours. Billable hours = 1,748 × (1 − 0.28) = 1,258.56 hours.

Result: About 1,258.6 billable hours per year, or 104.9 per month.

Interpretation: Client commitments totaling materially more than this would require longer working hours, fewer non-billable duties, or additional delivery capacity.

Should internal leadership meetings count as billable?

Count them as billable only when your client agreement allows you to invoice that time. Meetings for your own practice belong in non-billable time.

Why use working weeks instead of 52 weeks?

Working weeks make planned time off explicit. This avoids hiding vacation and holiday assumptions inside the non-billable percentage.

Can I use this for retainer work?

Yes. Convert each retainer into expected hours and compare the combined commitment with the annual or monthly billable capacity.

What happens if non-billable time is very high?

The available billable hours fall proportionally. A high value can be realistic for executives who spend substantial time on sales, networking, and practice management.

How is capacity different from revenue?

Capacity measures hours you could potentially bill. Revenue also depends on your rate, utilization of those hours, contract structure, discounts, and collections.