New Delhi, Oct. 16 -- A 30% salary hike may look like an obvious career move, but for a parent with a toddler, a better-paying job can come with a less visible cost. Longer commutes, additional childcare expenses and fewer evenings with the child can reduce the financial benefit of switching jobs.

The dilemma raises a practical personal-finance question. How much of a higher salary does an employee actually get to keep after income tax and the additional costs of taking up a new job?

The answer depends on more than the headline increment. The salary structure, tax liability, commuting expenses and childcare arrangements all affect the amount left over at the end of the month. A parent must also weigh these monetary gains against the tim...