Two offers, side by side. One pays $95,000 in Austin. One pays $105,000 in San Jose. The second is obviously better — it is ten thousand dollars more.
Except it very often is not, and the reasons are boring enough that people skip them: state tax, commute, and the fact that a dollar buys different amounts of housing in different places.
State tax is the easy part, and it is bigger than people think
State income tax ranges from zero — Texas, Florida, Washington, Nevada, and a handful of others — to over 13% at California's top bracket. On a six-figure salary, moving between the extremes is worth more than most annual raises.
On $105,000, California state tax runs into five figures. On $95,000 in Texas, it is zero. Before anything else is counted, that $10,000 gap has already closed and started reversing.
This is the single most mechanical part of the comparison, which is why it is worth doing first: no estimation, no judgment, just a rate applied to an income.
Federal tax quietly narrows every gap
Federal tax is progressive, so the higher offer is taxed harder at the margin. The extra $10,000 does not arrive whole — it arrives taxed at your top marginal rate, which for a mid-career salary is typically 22% or 24%.
The practical rule: a raise is worth roughly two-thirds to three-quarters of its headline value once federal and FICA come out. Any comparison done in gross dollars is systematically overstating the difference between two offers.
Cost of living is where it actually gets decided
Tax is measurable. Cost of living requires more care, because the aggregate index everyone quotes is misleading in a specific way: it blends housing with everything else, and housing is where nearly all the variance lives.
Groceries, fuel, and a haircut differ modestly between US metros. Rent and mortgages differ enormously. If you are comparing a high-cost and a low-cost metro, the honest comparison is not "cost of living is 40% higher" but "the specific home I would live in costs this much more per month."
Look up actual listings for the actual neighbourhood you would live in. It takes twenty minutes and it is worth more than any index.
The commute is a pay cut nobody itemises
This is the factor most likely to be missing from a spreadsheet comparison, and it hits twice.
It costs money — fuel, tolls, parking, vehicle wear — which the calculator subtracts from take-home. And it costs hours, which the calculator adds to the denominator of your real hourly wage.
An extra forty-five minutes each way is about 1.5 hours per working day, roughly 375 hours a year. That is more than nine forty-hour weeks of your life, unpaid. Against that, a $10,000 raise is buying your time at under $27 an hour before tax — quite possibly less than the job itself pays you.
The offer with the shorter commute frequently wins even at a lower salary, and people are consistently surprised by how large the effect is.
Benefits are salary in a different costume
Two things routinely swamp a five-figure salary difference:
Employer retirement match. A 6% match on $95,000 is $5,700 a year of real compensation. An offer with no match needs a meaningfully higher salary to break even.
Health insurance. The difference between a plan with a $500 deductible and one with $5,000, plus the monthly premium difference, is commonly worth several thousand dollars a year — and considerably more in a year when you actually need care.
Ask for the full benefits summary before comparing. An offer letter alone is not enough information to make this decision.
What the comparison actually outputs
When you run two offers through the calculator, both are reduced to the same unit: what one hour of your life is worth under each.
That is the comparison that survives contact with reality, because it has absorbed the tax difference, the job costs, the commute in both money and time, and the unpaid hours. Two offers that look ten thousand dollars apart routinely land within a couple of dollars an hour of each other — and sometimes the "smaller" one comes out ahead.
What the numbers cannot tell you
This deserves saying plainly: the calculator compares compensation, and jobs are not only compensation.
Career trajectory, the quality of the people you would work with, whether the work interests you, proximity to family, whether the industry is growing or shrinking in that city — none of that is in the model, and any of it can legitimately outweigh a few dollars an hour.
What the number does is stop you from making a bad financial decision while believing you made a good one. If you choose the lower real wage with your eyes open because the job is better, that is a fine decision. Choosing it by accident because the gross salary looked bigger is not.
Ready to compare? Open the calculator and use the job comparison mode.