A Systematic Withdrawal Plan (SWP) calculator is an online tool that helps investors plan regular monthly withdrawals from their mutual fund corpus — estimating how long the corpus will last and what the remaining balance will be at any point in time, given the initial corpus, monthly withdrawal amount, and assumed rate of return on the remaining invested balance. An SWP allows investors to redeem a fixed amount from their mutual fund at regular intervals (monthly, quarterly, or annually) while the remaining balance continues to earn returns — creating a predictable income stream similar to a pension, without requiring the investor to liquidate the entire portfolio at once. In India, SWPs from equity-oriented hybrid funds or balanced advantage funds are a popular retirement income strategy — particularly for investors who want inflation-beating returns on the remaining corpus while drawing a regular income. The SWP calculator demonstrates the critical importance of the withdrawal rate relative to the portfolio's return — if withdrawals exceed returns, the corpus depletes over time; if returns exceed withdrawals, the corpus grows even while income is being drawn. Tax efficiency is another advantage of SWP over non-cumulative FDs — only the capital gains component of each withdrawal is taxed, rather than the entire withdrawal amount.