The hardest question in a negotiation is also the easiest one to get wrong. A candidate in Mumbai says “I need ₹1 lakh in hand, non-negotiable.” What CTC do you actually have to sign off on? Guess low and the offer bounces at the last step. Guess high and you have overpaid and blown the band for the next hire. This calculator solves it exactly.
How the reverse math works
Take-home is easy to compute forwards: start with CTC, strip out employer PF and gratuity to get gross, then remove employee PF, professional tax and income tax. Running it backwards has no clean formula because the tax slabs are piecewise, so the calculator does what a payroll analyst would do by hand, only faster. It searches for the CTC whose forward take-home lands exactly on your target, then reports it.
For ₹1 lakh a month in hand in Mumbai, the answer comes out near ₹14.95 lakh under the new regime. That is roughly a 80% take-home ratio, which holds up well until the package climbs into the 30% slab and surcharge territory, where the ratio starts sliding.
The regime picks itself
The tool solves the target twice, once under each regime, and reports the cheaper package. This matters more than people expect. To deliver the same ₹1 lakh a month, the old regime with no declared deductions would need over ₹17 lakh of CTC, more than ₹2 lakh above the new-regime answer. That single comparison tells you not to structure this offer on the old regime, and it tells you before you have wasted a round of back-and-forth.
Location sits in the calculator because professional tax is state-specific. Maharashtra caps it at ₹2,500 a year, Karnataka at ₹2,400, and Delhi does not levy it at all. The effect on the required CTC is small but real, and at scale across a hiring plan it is worth getting right rather than assuming.
What the number assumes
The package is built on the standard structure: basic at 50%, HRA at 50% of basic, statutory PF, no rent-based HRA exemption and no itemised old-regime deductions. That is the honest baseline for a fresh offer where you do not yet know how the candidate will invest. If they later declare 80C investments or claim HRA on real rent, their take-home rises above the target, which is the safe direction to be wrong in.
Once you have the required CTC, confirm the full split in the take-home salary calculator, or compare regimes head to head in the in-hand salary optimizer. If you are starting from a gross rather than a take-home, the gross to CTC calculator builds the package the other way around.