Works backwards from a target net salary — say ₹1L a month in hand — to the gross CTC that actually delivers it after tax, useful when negotiating an offer against a specific take-home number.
Since tax isn't a flat percentage (it's slab-based with a rebate cliff and surcharge bands), there's no simple formula to invert directly, so the calculator searches for the gross salary whose post-tax net matches your target, converging to within a rupee.
Once you're past the 87A rebate threshold, every additional rupee of gross is taxed at your marginal slab rate before it reaches your take-home, so hitting a specific net number — especially a round one like ₹1L/month — usually needs a noticeably larger gross than a naive percentage estimate suggests.
This works on gross taxable salary versus net take-home; employer PF/gratuity contributions are usually part of CTC but not part of your monthly in-hand pay, so factor them in separately when comparing the gross figure here to a CTC offer.
Figures are estimates for informational purposes only, based on the assumptions you enter, and are not tax advice. Consult a Chartered Accountant or the Income Tax e-filing portal before filing.