Fractional CTO Cost: A Break-Even Worksheet

Most “fractional CTO ROI” calculators multiply made-up savings percentages and print a large number. This one does less. It converts a quote into a yearly cost, sets that against a published figure for a full-time hire, and tells you how many hours a week the two options cost the same. It cannot tell you whether the engagement will be worth it. Section three explains why.

1. The worksheet #

Two inputs come from the U.S. Bureau of Labor Statistics. The rest are yours, and the numbers in the script that are not from BLS are marked as examples.

• Median wage: $175,140 a year for computer and information systems managers, a group that includes CTOs, in May 2025 (BLS Occupational Outlook Handbook).
• Wage share of employer cost: 68.5 percent for full-time private-industry workers in June 2026, with benefits making up the other 31.5 percent (BLS Employer Costs for Employee Compensation).

# Inputs 1-2 are published BLS figures. Inputs 3-5 are yours: replace them.
median_wage    = 175_140 # BLS OOH, computer and information systems managers, May 2025 median wage
wage_share     = 0.685   # BLS ECEC, June 2026: wages are 68.5% of employer cost, full-time private industry
recruiting_fee = 0       # your recruiter's quote, if you use one
hourly_rate    = 250.0   # EXAMPLE ONLY: the rate you were quoted
weeks          = 52      # weeks the engagement would run

money = ->(n) { "$" + n.round.to_s.reverse.scan(/\d{1,3}/).join(",").reverse }

loaded = median_wage / wage_share + recruiting_fee
puts "Full-time, loaded (first year): #{money.(loaded)}"
puts "Break-even: #{(loaded / hourly_rate / weeks).round(1)} hours a week at #{money.(hourly_rate)}/hour"
puts
puts "hours/week  fractional/year  vs full-time"
[5, 10, 15, 20, 30].each do |h|
  cost = hourly_rate * h * weeks
  puts format("%-11d %-16s %s", h, money.(cost), cost < loaded ? "cheaper" : "more expensive")
end

We ran it with Ruby 4.0.6. Output:

Full-time, loaded (first year): $255,679
Break-even: 19.7 hours a week at $250/hour

hours/week  fractional/year  vs full-time
5           $65,000          cheaper
10          $130,000         cheaper
15          $195,000         cheaper
20          $260,000         more expensive
30          $390,000         more expensive

The $250 an hour is a placeholder, not a market rate, and we do not have an authoritative source for what fractional CTOs charge. Put in the number you were quoted. The break-even line is the useful one: at the example rate, the two options cost the same at about 20 hours a week. Above that, you are paying for a full-time person without the full-time commitment.

2. What the worksheet leaves out #

It is deliberately partial. Before you trust it, add what it omits:

• Equity. A full-time CTO at an early-stage company usually receives some. We have no source for typical amounts, so ask a startup lawyer or your investors.
• Recruiting. The recruiting_fee line is zero because we have no sourced figure. If you would use a recruiter, enter the quote.
• Ramp-up. A new full-time hire takes time to become useful and a search can take months. The worksheet counts first-year cost as if the hire started on day one.
• The BLS caveat. The wage is a median for a broad occupation across all industries, and the benefit share is an average across all full-time private-industry workers. Neither is a startup CTO offer.

3. Why we do not print a payoff number #

A fractional CTO’s value comes from decisions: an architecture avoided, a bad hire not made, a rewrite not started. Nobody has a clean count of how often those happen, and a figure like “pays off in 3 to 6 months” depends on the specific person and the specific company. If a source gives you a precise return with no method behind it, treat it the way you would treat a testimonial with no name.

You can still estimate, with your own inputs. Write down the decision the engagement is meant to improve, say “should we rebuild the payments module in-house?”, and estimate its cost under the two outcomes. Then ask the candidate how they would help make that decision and what they would deliver in the first 30 days. If the answer is a named document or a decision record, you can check whether it arrived. If the answer is “strategic guidance”, you cannot.

4. Questions to ask any fractional CTO candidate #

1. What will exist at the end of the first month that does not exist now? A document, a decision, a hire, a fixed process.
2. How many other clients do you work with, and how will you cover an incident? Divided attention is the real cost. You are entitled to know the load.
3. Can I speak to someone you worked with recently? A named reference who can say what changed is better than a testimonial page.
4. Will you write code, or only review? Both can be right. You need to know which you are buying.
5. How will the knowledge stay with us when you leave? Ask for decision records and a named internal owner per area.
6. What would make you tell me I do not need this? A candidate who can name conditions under which you should not hire them is easier to trust.

5. When to skip it #

If your team ships on schedule and you have a senior engineer who decides things, a CTO of any kind is a cost with nothing to pay for. If the real gap is more developers, the cheaper move is more developers. Our own offer is an embedded team of senior full-stack developers who drive the development while you run the rest of the business: see how we work. JetThoughts is rated 4.8/5 on Clutch.

For the conceptual comparison, read fractional CTO vs full-time CTO.

Sources #

• U.S. Bureau of Labor Statistics, Computer and Information Systems Managers, May 2025 median wage and occupation description.
• U.S. Bureau of Labor Statistics, Employer Costs for Employee Compensation, June 2026, full-time private-industry wage and benefit shares.