Using the income-tax calculator for a mid-year job switch

One Tax Year, two payrolls

Tax Year 2026-27 (FY 2026-27, AY 2027-28) runs from 1 April 2026 to 31 March 2027. A March joining or a September switch still lands in the same year. Each employer withholds on what they see; neither automatically knows the other’s salary unless you declare previous income. Under-withholding mid-year often means a balancing payment at filing time.

The site calculator is for a simplified full-year gross picture—not a substitute for combining both Form 16s and AIS when you file.

How to use the calculator after an offer

Add expected gross from employer A for months worked plus employer B for the rest (include joining bonus in the year it is taxable). Pick new vs old regime the way you plan to file. If HRA or 80C only apply for part of the year, do not enter a full-year fiction—use a conservative deduction total.

Compare that rough liability with what both payrolls are likely to deduct. The gap is your planning number for advance tax or a year-end top-up.

Documents that close the loop

Keep both Form 16s, joining/relieving letters, and proof of investments declared to either payroll. Tell the new employer about prior income so TDS can adjust. Re-run the calculator if the CTC revision or bonus timing changes before 31 March.