Deposits, loans and the statutory calculations that come up at work: FD and RD maturity, PPF, home loan EMI, gratuity and HRA exemption. Every one runs in your browser, so the figures you type are never transmitted.
No rate is baked in. PPF and small savings rates are reset by the government every quarter, so each tool takes the rate as an input and says so, rather than quietly going stale.
None of these are financial or tax advice, and none of them recommend a product. They compute a figure from the numbers you enter, using the standard formula, and show enough working that you can check it. Expect small differences against a bank or fund statement: institutions round at different points and may apply fees these calculators know nothing about, so treat a result as the right order of magnitude and the statement as the authority.