Is a Second Income Worth It? The Childcare-and-Commute Math
beginner A second job's salary looks like it lands on top of a household's finances dollar-for-dollar. It doesn't. Because a household files one joint tax return, the second earner's income is taxed starting at whatever bracket the FIRST earner's income already reached — never at the household's original, lower rate. And the job itself has costs that exist only because it does: childcare, a second commute, work clothes, more takeout. This lesson nets both out against the raw salary and answers the real question — not "what does the job pay," but "what does it actually add." The simulator charts a dashed 45° line for naive gross pay against the real, bent-and-shifted line for what the household actually keeps, and prices an effective hourly wage after everything — a number that can be shockingly low, or even negative.