Start from the monthly take-home you actually want in your bank account, and find out the CTC figure you need to negotiate for.
We work backward using the same employer PF (12% of basic) and gratuity (4.81% of basic) assumptions as our CTC to In-Hand calculator.
Recruiters quote CTC because it's the number that matters to the company's budget, but your rent, EMIs and daily expenses are paid out of your in-hand salary, not your CTC. Two offers with the same CTC can leave very different amounts in your account depending on the basic pay split, PF structuring and bonus timing. Flipping the calculation, and starting from the take-home you need, gives you a concrete number to hold your ground on during salary discussions.
Because income tax itself depends on gross salary, there's no single line formula to invert. So this tool runs the CTC to in-hand calculation many times over a range of CTC values, a quick binary search, until it lands on the gross and CTC that would produce your target take-home pay under your chosen tax regime.
Recruiters talk in CTC while your expenses are paid from in-hand salary. Working backward from the take-home you need tells you the minimum CTC to hold out for.
It's a close estimate based on typical basic pay, PF and gratuity assumptions. Your actual employer's structure can shift the real number by a few percent.
Use it as a floor to negotiate from. Round it up slightly to leave room for the employer's own PF and gratuity treatment.