What are the 3 formulas of HRA?

There are 3 formulas to calculate the tax-exempt House Rent Allowance amount:

1. Actual HRA received or rent paid, whichever is lower: This means the amount of HRA received from your employer, or the actual rent you pay annually for your accommodation - whichever amount is lower can be exempted from tax.
2. Excess rent paid over 10% of basic salary: If the rent you pay annually exceeds 10% of your basic salary, the excess amount can be exempt from tax.
3. 50% of basic salary (40% for non-metro): If you live in a metro city, up to 50% of your basic salary can be exempted from tax as HRA. For non-metro cities, this limit is 40%.