How the FD / RD Calculator Works
AnyTool FD / RD Calculator handles both Indian deposit types in the browser. For a Fixed Deposit it uses compound interest credited quarterly — the standard at most Indian banks — so the maturity is M = P × (1 + r/n)^(n·t), where P is the principal, r the annual rate as a decimal, n the compounding periods per year (4 for quarterly, also 12, 2 or 1) and t the tenure in years; a simple-interest option (M = P × (1 + r·t)) covers short tenures. For a Recurring Deposit each equal monthly installment earns the same quarterly-compounded interest for its remaining tenure, M = Σ P × (1 + r/4)^(remaining months ÷ 3), which the tool computes with a transparent month-by-month loop that adds the installment and accrues the equivalent monthly factor of the quarterly scheme. A senior-citizen toggle adds ≈ 0.50% to the rate, the effective annual yield (APY) is shown, and a 0% rate cleanly returns just the money deposited. All arithmetic is pure client-side JavaScript in a reusable deposit engine.
- FD: M = P × (1 + r/n)^(n·t), quarterly by default (n = 4); also monthly / half-yearly / annual / simple
- RD: M = Σ P × (1 + r/4)^(remaining months ÷ 3) via a month-by-month quarterly-compounding loop
- Senior-citizen +0.50% toggle and an editable rate (7% default)
- Effective annual yield (APY) shown; 0% rate returns just the deposits
- All math is client-side JavaScript in a reusable engine — no server round-trip
