SIP calculator gives an estimate of future corpus, not a guarantee, as returns depend on market

A systematic investment plan (SIP) is a method of investing in which a fixed sum is put into a mutual fund every month. An SIP calculator app shows how much the deposited amount could grow over a set period. It gives an idea of the final sum, but the figure is not guaranteed. Mutual fund returns depend on market conditions, so the amount in hand may be lower or higher.

The calculator works on three inputs: the monthly instalment, the tenure and the assumed rate of return. It derives a monthly rate from the assumed annual rate and applies it to each instalment, assuming all instalments are paid on time. The estimated value of each instalment is then added up. Each instalment is taken to earn returns from its deposit date to the end of the calculation, so older instalments get more time to grow.

Take an example. Investing Rs 5,000 a month for ten years makes 120 instalments. At an assumed annual return of 10%, the calculator gives an estimate of what these instalments could add up to. It is not a prediction of how a fund will perform.

The inputs have a direct bearing on the result. Other things being equal, a higher monthly amount generally gives a higher estimate. Tenure also matters. Over a longer period, the early instalments get more time to compound, but this does not remove market risk. The rate of return has a large effect: even a small change in it can make a big difference to the figure many years later. A high rate should not be entered just to get a desired result.

Some calculators also let users choose how often the instalment is paid, and an annual step-up can be added. This makes it easier to compare different ways of saving. In the end, the result rests only on the inputs and assumptions.

Compounding means the return earned on an investment can itself earn further returns. In an SIP, each instalment starts compounding from its deposit date. The first instalment gets the longest time to grow and the last gets the least. Over a long period this effect becomes more visible. But mutual fund returns do not arrive at a fixed rate every month. The calculator simplifies this by applying a single assumed rate over the whole period.

That is why the output is only an illustration. The calculator cannot say how an investment fund will perform. It does not account for market ups and downs, economic conditions, interest rates and changes within the fund, so it gives only an estimate.

The scheme's costs, changes in the portfolio and the timing of the investment also affect the amount. Some calculators take a simple approach without counting all costs and taxes. Before investing, one should read the scheme documents and check the charges and taxes that apply.

An SIP calculator app is most useful for trying out different scenarios. By changing the monthly amount, tenure and expected return, users can see how the figures change. This shows how within reach a savings goal is, but it gives no assurance that the goal will be met.

Investors can try low, medium and high rates of return to understand how far the final amount depends on the market. They can also check whether paying the instalments is affordable. Many stock and mutual fund apps have a calculator, but it does not say whether a scheme suits your purpose, time horizon and risk appetite.

Before starting any SIP, one should look at the scheme's objective, asset allocation, risk, charges and past performance. A good past record does not mean an investment will perform the same way in future. In sum, an SIP calculator's estimate rests on the instalment, the tenure and the expected rate of return. Actual returns are set by the market, so the total amount can differ. 5paisa Alpha offers tools to view investment information, but risk, costs and the suitability of a fund have to be assessed by the investor.