Income Tax calculation for individual for new tax regime as well as old tax regime. If you are calculating tax manually with help of tax slab provided by the government, this article and income tax calculator is for you. But, to calculate the true and correct tax with help of tax slab provided by the government is very lengthy and boring process. In addition to the same, if your income is above Rs 50 lakhs, you have to calculate the Marginal relief. You have to take care while calculating income tax. While you calculate income tax you have some questions like: