SIP Calculator

A systematic investment plan is one of the most common ways people build wealth, because it turns investing into a fixed monthly habit rather than a decision that requires conviction on any given day. The SIP calculator projects what a regular monthly contribution could be worth, and just as importantly, shows you how much of the final balance was growth rather than deposits.

The core mechanic is that each monthly contribution is a small deposit that then starts earning its own return. Over a long enough period, the contributions themselves become a smaller and smaller share of the total. In the default scenario of $500 a month at 12% for fifteen years, you put in $90,000 and the balance is considerably higher than that, and that gap is the compounding working for you.

The expected return is the input that deserves the most scepticism. It is a hypothetical, not a forecast. Long-run broad equity index averages have historically landed somewhere around 7–8% a year after inflation in major markets, but past averages are a poor guide to any specific period, and a bad decade can look very different from the average line. Enter the rate you are genuinely comfortable planning around rather than the most optimistic one.

The annual contribution increase field models the most powerful habit in the whole system: raising your monthly amount every year. Even a 5% annual step-up makes an enormous difference over a long horizon, and it is far more achievable than committing to a much larger figure from day one. This is the effect that has made employer pension schemes so effective.

This calculation assumes monthly compounding, contributions at the end of each month, and a constant annual return. It ignores fees, fund expense ratios, taxes, and inflation. Real returns fluctuate, and in some years they are sharply negative, which is exactly why regular investing works: you keep buying at a lower price automatically.