How it works
Three amounts are computed and the least of them is your exemption: the HRA you actually received, the applicable share of salary, and rent paid less 10% of salary. The rest of the allowance is added to your taxable income.
The table names the binding limit, which is the actionable part. If limit three binds, every extra rupee of rent raises your exemption by a rupee. If limit one or two binds, extra rent does nothing for your tax at all — a distinction worth knowing before negotiating either a salary structure or a lease.
More detail
Salary here means basic plus dearness allowance, not CTC. Because HRA is typically set as a percentage of basic, a salary structure with a low basic caps the exemption through limits one and two simultaneously.
The calculator also reports the rent at which the exemption would reach its ceiling, so you can see how much headroom is left.
To fold this exemption into the regime decision, use the regime comparison calculator.
To see what the taxable part costs you, see the income tax calculator.
To weigh renting against buying altogether, try the rent versus buy calculator.