Full-time, fractional or interim: which CTO do you need?
Choose your stage, team size and what the role must cover, from architecture and hiring to AI strategy and investor due diligence. See the year-one cost of each option, how well each covers those responsibilities, and how many strategic days a month your situation needs.
Size your technology leadership
Tell us what the role must cover. Salary and day rate start from typical figures you can replace.
- Full-time CTO$240,000
- Fractional CTO$70,000
- Interim, then permanent$300,000
- Doing without$40,000
- Full-time CTO88 / 100
- Fractional CTO62 / 100
- Interim, then permanent83 / 100
- Doing without10 / 100
- Full-time CTO$1,800
- Fractional CTO$1,200
- Interim, then permanent$1,600
- Doing without$2,200
- At 5 days a month you are slightly short of the 6.8 days this situation needs, which holds coverage at 62/100. A day or two more would close most of the gap.
- A full-time CTO scores 88/100 on coverage against 62/100 here, but costs $180,000 more in year one and is far harder to unwind if the fit is wrong.
- In year one a full-time CTO costs about 3.5 times the fractional option, including $41,000 of expected cost from a 30% chance of a wrong hire.
- A 4.0-month search leaves the seat empty for a third of the year or more. Interim or fractional cover can also run that search and interview candidates.
- Equity worth $50,000 a year is part of the full-time cost even though no cash leaves the bank.
- Doing without leaves 5 engineers without technical leadership. The indicative hidden cost is $40,000 a year in founder time, rework and drift.
- Doing without has a small bill but a high cost per strategic day: founders cover leadership in borrowed hours, and the team pays for the gaps in rework.
- AI strategy adds about 1.0 strategic days a month at the "Adopt AI tools" level. Ask any candidate how their own teams use AI coding agents and how AI-written code gets reviewed.
Indicative 2026 assumptions. A full-time CTO spends around 17 strategic days a month. Doing without is priced as founder time plus rework and drift in the team, which is an estimate rather than an invoice.
Indicative only. We will send the inputs above with your message so a senior engineer can sanity-check them.
Fractional CTO cost compared with the alternatives
Each option solves a different problem. The calculator prices all four, but the right choice depends as much on timing and workload as on cost.
| Full-time CTO | Fractional CTO | Interim CTO | |
|---|---|---|---|
| Typical commitment | Permanent, every working day | 1 to 10 days a month, ongoing | Most of the week for a few months |
| How you pay | Salary, benefits, equity, search fee | Monthly retainer or day rate | Premium day rate for a fixed period |
| Time to start | Commonly 3 to 6 months of searching | Usually within weeks | Usually within weeks |
| Best for | Large teams and deep product ownership | Early-stage companies and SMEs | Covering a gap or a transition |
| Main risk | An expensive wrong hire | Too few days for the workload | No continuity after they leave |
"Doing without" is the fourth option in the calculator. It costs nothing on an invoice but shows up as founder time, rework and slower decisions.
Why the answer changes from company to company
Team size
Every engineer adds leadership demand. Beyond a dozen, part-time leadership struggles with day-to-day hiring and people management.
Responsibilities
Architecture, hiring, security and investor support each take time. The calculator adds them up into strategic days a month.
AI ambition
Moving to AI-native delivery or adding AI to the product means choosing tools, setting review standards for generated code and writing data policies. That is real CTO work.
Wrong-hire risk
A mis-hired executive costs months of salary, a second search fee and lost momentum. Fractional and interim roles are far cheaper to unwind.
Time to hire
Senior technology searches often take months. The seat stays empty during that period, which is why interim cover is priced as a bridge to a permanent hire.
Equity
Startup CTOs usually expect meaningful equity. It does not come out of the bank account, but it is a real cost to founders and early investors.
From calculator result to a decision
Check the strategic days
If your situation needs fewer than about eight days a month, a full-time CTO will spend much of their time on work a senior engineer could do.
Look at coverage, not only cost
A cheap option with low coverage leaves real gaps. Pay attention to which responsibilities drag the score down.
Stress-test your assumptions
Raise the wrong-hire risk, lengthen the search and add the responsibilities you expect next year. See whether the recommendation holds.
Plan the transition
Often missedFractional leadership works best with an end state in mind: a documented architecture, a hiring plan and, eventually, a clear brief for a permanent CTO.
Questions we often hear
How much does a fractional CTO cost?
Most fractional CTOs charge a day rate or a monthly retainer for a set number of days. Day rates commonly range from several hundred US dollars in lower-cost markets to $2,000 or more in North America, so two to six days a month usually costs a fraction of a full-time package. Enter a real quote in the calculator to compare.
Is a fractional CTO worth it compared with a full-time CTO?
For early-stage companies and SMEs with small teams, usually yes: you get senior judgement for architecture, hiring and investors without a full salary, equity and search fee. Once the team grows past a dozen or so engineers, or technology is the core of a complex product, a full-time CTO normally becomes the better investment.
What is the difference between a fractional CTO and an interim CTO?
A fractional CTO works part-time on an ongoing basis. An interim CTO works close to full-time for a defined period, typically to cover a departure, lead through a critical phase or run the search for a permanent replacement and hand over to them.
Should a CTO own AI strategy?
In most small and mid-sized companies, yes. Someone senior has to decide where AI belongs in the product, how the engineering team uses AI coding tools, how generated code is reviewed and what data AI systems may see. When hiring or engaging a CTO, ask how their own teams work with AI in practice.
What does a fractional CTO do in a typical month?
A typical month mixes scheduled and on-call work: a planning session with founders, architecture and code reviews, interviews for open roles, a check-in with any agency or vendor, and time on security questionnaires or investor questions. The mix shifts with the company, which is why the number of days matters more than the job title.
When does a startup need a full-time CTO?
Common signals are a team heading past ten to fifteen engineers, technology becoming the main source of competitive advantage, or investors expecting a permanent technical co-founder or executive. Before that point, a fractional CTO or a strong lead engineer with senior advice is often enough.
Related reading and tools
Not sure how much CTO you need?
Send your calculator results and a little about your company. You will hear back within 24 hours with an honest view on whether fractional leadership fits, how many days it would take, and when a permanent hire makes more sense.
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