Why the headline hourly rate is misleading
Every engineer who considers going contract runs the same napkin math: "$150 an hour times 40 hours times 52 weeks is $312,000. That's way more than the $220k salary." Then they take the contract and are surprised when their take-home is lower than expected.
The gap comes from four places. First, contractors don't get paid vacation, sick days, or holidays — a realistic year is 48 weeks, not 52. Second, self-employment tax is 15.3% instead of the 7.65% W-2 employees pay, because the contractor covers both the employee and employer share of Social Security and Medicare. Third, health insurance costs $650–$1,900 per month out of pocket instead of ~$200. Fourth, there's no employer 401k match — which at 4% on a $220k salary is $8,800 of free retirement money each year.
Add it all up and a $150/hr contract billing 40 hours a week is roughly equivalent to a $220k salary in net take-home. Higher than the salary, but not by the $60k the headline suggests.
When contract wins on the money
- Very high hourly rates. Above $180–$200/hr, the gap becomes real. A $250/hr contract clears $350k gross and even after full SE tax and out-of-pocket insurance nets well above a $300k W-2 offer.
- Low-tax states. If you live in Texas, Florida, or Washington, your net take-home swings meaningfully in favor of the contract because state tax doesn't erode either side, but the contractor keeps a larger percentage overall.
- Multiple concurrent clients. If you can bill two clients at 30 hours each without doubling insurance or admin costs, the economics compound. This is where senior contractors clear $400k+ net.
- Married with a spouse on benefits. If your partner's employer covers health insurance, the $650–$1,900/mo insurance drag disappears — and contract becomes materially better than W-2.
When W-2 wins
- Equity is real and vesting. A $220k W-2 offer at a Series C company with $80k/yr of vesting RSUs is usually a much better deal than a $150/hr contract, even before considering the IPO upside.
- You have kids or a mortgage. Losing employer health insurance and long-term disability coverage matters a lot more when someone else depends on your income.
- You want to focus on the work, not the business. Contracting means invoicing, quarterly estimated taxes, chasing late payments, and running an LLC. Some engineers thrive on that. Many don't.
- You want unemployment insurance. If your industry is going through layoffs, W-2 employees get 26 weeks of unemployment. Contractors get nothing.
The tax reality every contractor learns the hard way
The single biggest surprise for new contractors is quarterly estimated taxes. There's no withholding. You owe federal and state taxes four times a year — April 15, June 15, September 15, and January 15 — and if you underpay by more than $1,000 in a year, you owe a penalty. Set aside 30–35% of every invoice in a separate account before you spend a cent.
The second surprise is self-employment tax. On the first ~$176,100 of net SE income, you owe 15.3% (12.4% Social Security + 2.9% Medicare). Above that, only the 2.9% Medicare portion continues, plus 0.9% Additional Medicare above $200k single. Half of the SE tax is deductible from your income tax bill, which softens the sting.
The third surprise is the QBI deduction. If your taxable income is below the 2025 phase-out ($243,725 single / $487,450 MFJ), you can deduct 20% of your qualified business income from your taxable income. This is a big deal — worth roughly $10,000–$20,000 in tax savings for a typical mid-six-figure contractor. Above the phase-out, engineering services are in the "specified service trade" category and the deduction is limited.
Health insurance is the make-or-break variable
For a single 35-year-old, a mid-tier ACA silver plan runs around $600–$700 per month in most states. If you have a partner on the plan, that jumps to $1,200–$1,400. A family of four is closer to $1,800–$2,100. Compare that to typical W-2 out-of-pocket costs of $150–$300 per month, and health insurance alone can swing a comparison by $10,000–$20,000 per year.
If you're contracting through an agency, ask if they offer group health coverage — some do, and the premiums can be materially cheaper than the individual ACA market. If your spouse's employer offers a family plan, that's often the cheapest path.
How to actually make the decision
Run the numbers with this calculator, but weight the non-cash factors honestly. Ask yourself:
- Do I have 6+ months of expenses saved? (Contract requires this — one client can drop you at any time.)
- Am I disciplined about setting aside taxes? (If the answer is "probably" — take the W-2.)
- Do I have another source of health insurance? (Spouse, VA, ACA subsidy at lower income.)
- How much do I value equity upside vs cash today? (Contract is cash-heavy, no upside. W-2 with equity is a call option.)
- How much do I value flexibility? (Contract lets you take a three-month break. W-2 doesn't.)
Most engineers who go contract end up preferring it. Most engineers who stay W-2 also end up preferring it. What matters is being clear-eyed about the trade-offs before you sign.