The full cost of college versus a trade flips by field — but “it depends on the field” is easy to say and hard to feel. So here is one concrete pairing, run all the way out: a welder against a mechanical engineer. Both figures are BLS medians; the math is the same engine the calculator uses. It’s a single example — your own numbers will differ — but it shows the whole dynamic in one place.
Two real starting points
A welder earns a median of $51,000 a year (BLS, May 2024). The job needs a high-school diploma plus technical and on-the-job training, so a welder can be earning within a year, often with little or no debt. A mechanical engineer earns a median of $102,320 (BLS, May 2024) — almost exactly double — but needs a four-year degree first, with its tuition, living costs, and the four years of wages forgone while studying.
That’s the whole tension in two numbers: the engineer earns far more per year, but starts four years and roughly $30,000 of debt behind. The question is how long the higher salary takes to erase that head start.
The head-start, in dollars
Set both paths going from the same day — one into a welding program, one into a four-year engineering degree — and track the cumulative cash position of each, year by year. The welder is earning by year one. The engineer is spending: tuition, living costs, and about $49,200 a year in forgone wages (what a high-school graduate earns instead, per BLS), for four straight years.
By the time the engineer graduates around year three, the welder is already roughly $400,000 ahead in cumulative earnings — about $404,000 at the low point. That’s not a rounding error or a head start you shrug off. It’s the price of the degree, and it’s far larger than the tuition alone. The engineer’s higher salary has to climb out of a four-hundred-thousand-dollar hole before it pulls even.
When the lines cross
It does climb out — but it takes twelve years. Running both paths forward at a shared 3.4% annual wage growth (the recent economy-wide figure, BLS Employment Cost Index), the engineer’s cumulative earnings overtake the welder’s around year twelve. Before that, the welder is ahead; after it, the engineer is, and the gap widens fast.
By year thirty, the engineer is ahead by roughly $1.5 million. That’s the case for the degree when the field pays like engineering: the head start is real and large, but a salary near double the trade’s overcomes it by mid-career and then compounds. This is the opposite end of the spectrum from a typical all-fields degree, which barely breaks even against the trades over the same thirty years — same arithmetic, a very different field.
One thing worth noticing about the growth rate
On most pairings, the wage growth rate you assume moves the crossover year a lot — it’s the single biggest assumption in the whole calculation. Here it barely moves it. Run this welder-versus-engineer comparison at 2%, 3.4%, or 5% growth and the crossover stays around year twelve; only the size of the final gap changes (from roughly $1.3 million to $1.9 million by year thirty).
The reason is the size of the wage difference. When one path earns nearly double the other, the gap is wide enough that the growth rate can’t change when they cross, only how far ahead the higher earner ends up. On a closer pairing — a typical degree against a typical trade — the growth rate is decisive, because the two wages are near enough that small differences in compounding tip the result. It’s a useful reminder that these calculators behave differently depending on how far apart the inputs are; the crossover is robust here and fragile elsewhere.
What this one example can and can’t tell you
This is welder versus mechanical engineer, at national median wages, as a gross-earnings comparison. It doesn’t model taxes (which would slightly trim the engineer’s lead), or unemployment, or the very real differences in physical demand, working conditions, and how artificial intelligence might reshape demand for each. It says nothing about which work you’d rather do. And it’s two specific occupations — a welder who moves into pipe welding or inspection, or an engineer in a lower-paying sector, would shift the lines.
What it does show is the shape of the decision in full: a large early lead for the trade, a crossover in the second decade when the field pays well, and a widening gap after. Change either wage and the crossover moves — sometimes by a little, sometimes off the chart entirely. Run your own pairing in the calculator with the fields you’re actually choosing between, and read the full-cost cornerstone for why the field, more than anything else, decides this.