How RD maturity is calculated
Banks and India Post compound recurring-deposit interest quarterly. Each monthly instalment earns interest for the months remaining until maturity:
M = Σ P × (1 + r/4)4 × (months remaining ÷ 12)
This calculator adds up that value for every instalment, which matches the method banks use.
RD vs SIP
An RD gives guaranteed, fixed returns, making it ideal for short-term goals and conservative savers. A mutual fund SIP can earn more over the long term, but its returns are market-linked and not guaranteed.