DayCents

Budgeting & Income

Is the Second Income Worth It Calculator

A second income is taxed at the household's marginal rate from the very first dollar, because the first income already used up the low brackets. Childcare, commuting and work costs come out of what remains. The gross salary is rarely the number that matters.

Federal plus state — the rate on the household's last dollar, not the first.

7.65% employed, 15.3% self-employed.

Shelters this much childcare from income and payroll tax.

Clothing, lunches, convenience spending, professional fees.

The second income nets

$23,010

35% of the gross salary survives everything.

This is one year in isolation. Continuous employment protects future earning power, Social Security credits and retirement contributions in ways a single year's net figure understates — and the employer 401(k) match on this salary is not counted here.

Gross salary
$65,000
Income and payroll tax
$19,273
Childcare
$19,200
Childcare after the FSA break
$17,718

The FSA shelters part of it from income and payroll tax.

Commuting
$3,000
Other work costs
$2,000
Effective hourly rate
$11.51

What the hours you actually work are paying.

Gross salary$65K
What you keep$23,01035%
Tax$19,27330%
Childcare$17,71827%
Commuting and work costs$5,0008%

How this calculator works

Tax is the household's combined marginal rate plus payroll tax, applied to the whole second salary — correct in principle because the second income stacks on top of the first. Childcare is the monthly figure × 12, reduced by the Dependent Care FSA saving, which is the sheltered amount × the same combined rate. Commuting and other work costs are subtracted, and the remainder is divided by hours × weeks for the effective hourly rate.

A single blended marginal rate stands in for progressive brackets, and the Child and Dependent Care Credit is not modelled — it can be worth more than the FSA at lower incomes. Employer benefits attached to the second job, notably the 401(k) match and health coverage, are excluded and would raise the figure.

Try an example

Frequently asked questions

Is a second income worth it after childcare?

Often less than the salary suggests, and occasionally not at all in the years with two children under school age. The second income is taxed at the household's top marginal rate from the first dollar, and childcare is paid from what is left. A $65,000 salary can net closer to $23,000.

Why is the second income taxed so heavily?

Because the household's brackets are already partly filled by the first income. There is no second set of low brackets — the second salary stacks on top, so its first dollar is taxed at the rate the first salary's last dollar reached.

What is a Dependent Care FSA worth?

It shelters up to $5,000 of childcare from income and payroll tax, saving roughly $1,500 at a 30% combined rate. It is use-it-or-lose-it and must be elected at open enrolment. The Child and Dependent Care Credit is an alternative, and you cannot claim both on the same expenses.

Should I quit if the number is negative?

Not on this figure alone. Childcare costs collapse when children start school, while a career gap depresses earnings for a decade or more and reduces Social Security credits and retirement contributions. A break-even year in an eighteen-year arc is not a losing proposition.

What does this leave out?

The employer 401(k) match on the second salary, employer health coverage, career progression, and the value of both partners having independent income. On the other side, it also omits the unpaid work that childcare replaces, which is real even when it is not priced.

Disclaimer: DayCents provides this calculator for educational purposes only. Results are estimates based on your inputs and the stated assumptions — they are not financial advice, a quote, or an offer of credit. Consult a qualified financial professional before making major money decisions.