What Does an Empty Engineering Seat Cost? A Cost-of-Vacancy Calculator for CTOs
At the median time to fill, an empty software engineering seat represents about $14,500 of salary-equivalent capacity, and three seats about $43,600. Here is the formula, a plug-in table, what the number leaves out, and how to present it to finance.
What Is the Cost of Vacancy and How Do You Calculate It?
Cost of vacancy is the value of the work an empty seat is not doing. The simplest version prices that work at the salary you would pay. Stack Overflow's guide to the cost of vacancy shows the method with a worked example: annual salary divided by 260 working days, multiplied by the days to hire.
We use calendar days instead, for a practical reason: the time-to-fill benchmarks below are counted in calendar days, so dividing by 365 keeps the units consistent. The formula is annual salary divided by 365, multiplied by the days the seat stays empty, multiplied by the number of seats.
What Is the Salary-Only Floor for a Software Engineer?
The US Bureau of Labor Statistics reports a median annual wage of $135,980 for software developers in May 2025. Divided by 365, that is about $373 per calendar day for one seat.
For the days, use two benchmarks. SHRM reports a median time to fill of 39 calendar days for nonexecutive positions. HR Dive, reporting on Employ's hiring benchmarks, puts the average at 63.5 days in 2025. Neither is specific to software, so replace them with your own time to fill if you have it.
| Open seats | 39 days (SHRM median) | 63.5 days (Employ average) |
|---|---|---|
| 1 seat | About $14,500 | About $23,700 |
| 3 seats | About $43,600 | About $71,000 |
| 5 seats | About $72,600 | About $118,300 |
What Does the Number Leave Out?
Most of the real cost. The table prices the capacity at salary, but the work you are waiting for is worth more than the salary, or you would not have opened the role. It leaves out delayed delivery, revenue or customer commitments tied to the roadmap, overtime and burnout on the engineers who stay, recruiter fees and the interview time your own team spends.
Treat it as a floor, not an estimate. To go beyond it, add your own line: the weekly value of the roadmap items blocked by the empty seat. That number is yours to supply, and it is usually the one that changes the decision.
Key Takeaways
- Cost of vacancy is salary divided by 365, multiplied by empty days and seats
- One software engineer seat is about $373 of salary-equivalent capacity per calendar day
- The salary-only figure is a floor that excludes delayed delivery, overload and recruiting costs
Is a Vacancy or a Bad Replacement More Expensive?
A rushed hire can cost more than the vacancy. Gallup states that the cost of replacing an individual employee can range from one-half to two times the employee's annual salary, and calls that a conservative estimate. It is a 2019 estimate for the general workforce, not for engineers specifically. Applied to a $135,980 salary, the range is about $68,000 to $272,000.
The lesson is not to hire slowly. It is to price both risks. A fast route that includes a short paid trial and a replacement window lowers the chance that a rushed placement turns into the more expensive problem.
How Does Faster Capacity Change the Math?
Engineers can typically start within one to two weeks of first contact; a full team usually takes two to four weeks. Against the 39 to 63.5 days above, the difference is weeks of capacity you would otherwise be waiting for.
StepTo's staff augmentation starts from $4,500 per developer per month, with a 3-month minimum and weekly billing, so the minimum commitment is $13,500 per developer over the first three months. StepTo's own engagement figure is 36-51% below hiring in Western Europe or the US. The salary benchmark in this article is a US figure, so the comparison here is about timing, not a like-for-like price. For a cost comparison, see dedicated team vs in-house and the pricing page.
We compare the hiring timelines in how long it takes to hire software developers, and the full total-cost picture in our outsourcing total cost of ownership model.
Which Roles Should You Fill Fast and Which Slowly?
Fill fast when the empty seat blocks a dated commitment and the work has clear edges. Fill slowly when the role owns architecture or product direction for years, where a wrong choice costs more than a few weeks of delay.
A common split is to cover the dated work with external capacity now and run the search for the core role in parallel. That way the schedule does not depend on how long the single hardest hire takes.
How Do You Present It to Finance?
Use one paragraph with your own inputs. For example: we have [number] open engineering seats; at our time to fill of [days], the salary-only cost of vacancy is [amount]; the roadmap items blocked are worth [value] per week; adding external capacity starting within [period] reduces the exposure, with a minimum commitment of [amount] and a notice period of [period].
Finance teams respond to a number they can audit. Keep the formula visible, state that the salary-only figure is a floor, and separate the benchmark inputs from your own.
What Is Your Own Number?
Replace the benchmarks with your time to fill, count the seats and add the weekly value of what is blocked. Send us the role, the stack and the monthly cost of delay you computed on our contact page and we will map it to a start window, or read about staff augmentation first.
Building a team in Eastern Europe?
StepTo builds dedicated nearshore engineering teams in Belgrade, Serbia. Engineers start in 2-4 weeks, with a two-week paid trial and from $4,500 per developer per month.
