PPF has a tenure of 15 years . We select a Figure and invest it and we calculate it on the current interest rate and plan accordingly to the amount we will receive on the maturity. Even when we use ppf calculator its the same thing we have a final goal in mind and we work towards it by investing consistently. Every month or year . But If the rates drop in the near future which will eventually happen it will drastically affect our outcome . So how do we know that that will be stable.How Low Do you guys think it may drop in the coming 15 years.