A Mechanical Engineer earning $120K/year in Massachusetts takes home $87,195 after all taxes. That’s $7,266/month, with an effective tax rate of 27.3%.
The estimated median salary for Mechanical Engineers in Massachusetts is $109K (adjusted from the national median of $92K using Massachusetts’s cost-of-living index of 118). At $120K, you’re earning 10% above the state-adjusted median for this profession.
You’re earning above the median, suggesting you’ve moved beyond entry-level. As your career progresses, each raise will be taxed at your marginal rate, so understanding your bracket position helps you evaluate the true value of promotions and raises.
Filing as married filing jointly on $120K (single earner) saves you $7,585/year ($632/month) compared to filing single. This marriage bonus comes from the doubled standard deduction ($32,200 vs $16,100) and wider lower brackets.
Mechanical engineers who hold a Professional Engineer (PE) license can deduct licensing and continuing education costs if self-employed. Patent bonuses or invention awards from your employer are taxed as ordinary income. Engineers who travel to job sites or manufacturing facilities should track mileage if self-employed — the 2026 standard mileage rate can add up to significant deductions. If you receive a signing bonus when changing employers, it’s withheld at the 22% supplemental rate regardless of your actual bracket.
At #38 out of 50 states for take-home pay on a $120K salary, Massachusetts is in the bottom half for take-home pay. You’d keep $6,000 more per year in Alaska (#1), or $500/month.
After adjusting for cost of living, Massachusetts ranks #45 in purchasing power. That’s a drop from #38 in raw take-home — Massachusetts’s higher cost of living erodes some of your advantage.