An NPS (National Pension System) calculator is an online retirement planning tool that helps subscribers estimate the pension corpus they will accumulate under NPS by retirement age (60 years), and the approximate monthly pension they can expect — based on their monthly contribution, current age, expected return on NPS investments, and the annuity rate at retirement. NPS, regulated by the Pension Fund Regulatory and Development Authority (PFRDA), allows subscribers to choose their asset allocation among equity (up to 75% for Active Choice), government bonds, and corporate bonds. At maturity, subscribers must use at least 40% of the accumulated corpus to purchase an annuity from a PFRDA-empanelled insurer, with the remaining 60% available as a lump sum (tax-free). The NPS calculator models both the accumulation phase (showing corpus growth through compounding of contributions and returns) and the distribution phase (showing the estimated monthly pension from the annuity portion). NPS offers significant tax advantages in India: contributions up to ₹1.5 lakh qualify for Section 80C deduction, and an additional exclusive deduction of ₹50,000 per year is available under Section 80CCD(1B) — making NPS one of the most tax-efficient retirement savings instruments for investors in the 30% tax bracket who can benefit from the full ₹2 lakh combined deduction.