The moment a company decides to hire a software engineer, it anchors on one number: the salary. Everything else gets treated as overhead, as rounding error, as the cost of doing business. This is a significant mistake, and it distorts hiring decisions, team sizing, and build-vs-buy calculations across the industry.
The fully-loaded cost of a software engineer is typically 1.5 to 2 times their base salary. Some estimates push higher for senior engineers in high-cost locations with generous equity refreshes. Companies that don’t account for this aren’t being dishonest. They’re looking at the wrong line item.
The Visible Costs People Miss
Beyond salary, you have employer-side payroll taxes, which in the US run roughly 7.65% before you touch state-level obligations. Add health insurance, which for employer-sponsored family coverage averages well over $20,000 per year nationally according to the KFF Employer Health Benefits Survey. Add a 401(k) match, equity grants that vest and carry real dilution, paid time off (which is paid labor with zero output by definition), parental leave, hardware, software licenses, and whatever professional development budget your offer letter promises.
None of these are controversial. Every finance team knows them. The problem is that they’re accounted for at the org level rather than at the hiring-decision level, which means the person arguing for a new headcount is implicitly underselling the cost to everyone in the room.
The Invisible Costs That Actually Scale
The more interesting costs are the ones that don’t show up in any budget line. Every engineer you add increases coordination overhead for the existing team. This isn’t a soft concern. Fred Brooks documented the mechanics in The Mythical Man-Month in 1975, and every subsequent decade of software development has confirmed his math. Communication channels grow quadratically with team size. Meetings multiply. Code review queues lengthen. Onboarding a new engineer consumes somewhere between one and three months of a senior engineer’s productive attention, depending on codebase complexity and how well you’ve documented anything.
There’s also the cost of management bandwidth. Most organizations assume a senior IC becomes a manager when needed, as if the switch is free. It isn’t. You’re converting a high-output individual contributor into someone who will spend the majority of their time unblocking others, running one-on-ones, and translating strategy into tasks. The engineering output of that person drops to near zero for months.
Then there’s the long tail: the code that gets written. Every line an engineer produces is a future maintenance obligation. Hiring engineers doesn’t just add capacity, it adds surface area. The more engineers you have, the more code exists, and the more every future engineer must understand before they can safely change anything. This is why why legacy code maintainers earn more than greenfield devs is a real phenomenon and not a compensation anomaly.
The Attrition Multiplier
Industry-wide, software engineer tenure at tech companies averages somewhere between two and three years. When an engineer leaves, the replacement cost, including recruiting fees (typically 15-25% of first-year salary for external hires), interview time, and the productivity ramp, is commonly estimated at 50-200% of annual compensation depending on seniority and specialization.
This math should change how companies think about retention spending. A $10,000 raise to keep a senior engineer who was planning to leave isn’t a cost. Compared to the alternative, it’s almost certainly a return. But because retention spending shows up as increased salary expense and replacement costs are distributed across recruiting, management time, and reduced team velocity, most organizations never see the full picture in one place.
The productivity metrics that are quietly misleading you problem compounds here. Companies measure output in story points or tickets closed. They don’t measure the cost of ramp time, the tax on team velocity during a departure, or the institutional knowledge that walked out the door. So the attrition cost stays invisible even when it’s enormous.
The Counterargument
The reasonable pushback is that great engineers produce outsized returns, so obsessing over their fully-loaded cost misses the point. A strong engineer doesn’t cost twice their salary; they return ten times it. This is true for some engineers in some roles. It is not a general truth that scales across a department.
The argument also doesn’t change the analysis. If you’re making hiring decisions based on salary alone, you’re underweighting both the cost and the return. You might still hire, but you’d make different decisions about team size, tooling investment, and whether to build versus buy a given capability. Many companies that reflexively hire for every problem would find that a smaller, better-compensated, better-retained team would outperform them on both cost and output. Smart founders who build smaller than they could understand this intuitively. Most scaling companies forget it.
What This Actually Changes
The salary is the most legible part of engineer cost, which makes it the most dangerous anchor. The real number, fully loaded and including coordination costs and attrition risk and the maintenance obligations of every line of code written, is substantially higher. Not so high that hiring engineers is the wrong call. High enough that the decision deserves more rigor than most companies give it.
Build-vs-buy calculations deserve a fresh look. Team-size assumptions deserve scrutiny. And the next time someone says “we can just hire for that,” someone in the room should know what “just hiring” actually costs.
