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Mutual Funds & SIPs

What Is SIP? A Beginner's Guide to Systematic Investment Plans

SIP lets you invest a fixed amount in mutual funds every month. Here is how compounding, rupee-cost averaging and step-ups actually work.

By LetsInvest Research DeskUpdated 13 Sept 20261 min read

On this page (2 sections)

A Systematic Investment Plan (SIP) invests a fixed sum — say ₹5,000 — into a mutual fund every month automatically. Two forces do the heavy lifting: rupee-cost averaging (you buy more units when markets fall) and compounding over years.

What rupee-cost averaging actually does

The same ₹10,000 buys more units when the price is lower. Over three instalments that pulls your average cost per unit below the price you would have paid on day one.

₹100Month 1₹80Month 2₹120Month 3₹10,000 each month buys:100 unitsthe starting point125 unitsthe price fell83 unitsthe price rose308 units for ₹30,000 — an average cost of ₹97 a unitagainst ₹100 if you had bought the whole ₹30,000 on day oneIllustration only: ₹100, ₹80 and ₹120 are made-up prices, not a market path. Actual returns vary.

Scroll the chart sideways to see every year →

Illustration only. The three prices are made up to show the mechanism — they are not a market path and not a forecast. Real returns vary, and averaging only helps if you keep investing when the market falls.

How much can a SIP grow?

₹10,000/month for 15 years at 12% p.a. compounds to roughly ₹50 lakh, of which only ₹18 lakh is your contribution. Try the numbers yourself in our SIP calculator.

Move the sliders: what a SIP can grow into

Each bar is one year. The lower block is what you paid in; the upper block is what compounding added on top. Change any of the three assumptions and the chart, the totals and the table all move with it.

Total value ₹49,95,802 (₹18,00,000 paid in, ₹31,95,802 compounded)

₹12.50 L₹25.00 L₹37.50 L₹50.00 LY1Y8Y15
  • What you paid in
  • What compounding added
View the numbers as a table
YearPaid inValue
1₹1,20,000₹1,26,825
2₹2,40,000₹2,69,735
3₹3,60,000₹4,30,769
4₹4,80,000₹6,12,226
5₹6,00,000₹8,16,697
6₹7,20,000₹10,47,099
7₹8,40,000₹13,06,723
8₹9,60,000₹15,99,273
9₹10,80,000₹19,28,926
10₹12,00,000₹23,00,387
11₹13,20,000₹27,18,959
12₹14,40,000₹31,90,616
13₹15,60,000₹37,22,091
14₹16,80,000₹43,20,970
15₹18,00,000₹49,95,802

Illustration only. Assumes the return you set is earned every year, compounded monthly, and every instalment paid on time. Actual mutual-fund returns vary and can be negative for long stretches; past compounding is not a guide to future compounding.

Three rules that matter

  • Never stop SIPs in a crash — that is when averaging helps most.
  • Step up the amount 10% yearly as income grows.
  • Match fund risk to horizon: equity for 7+ years, hybrid/debt for shorter goals.

Educational content, not financial advice.

Key takeaways

  • Never stop a SIP in a crash. That is exactly when averaging helps most, and stopping is how most investors convert a plan into a loss.
  • Step the amount up about 10% a year as your income grows — the step-up compounds for as long as you keep it.
  • Match fund risk to your goal date: equity for seven years and more, hybrid or debt for anything shorter.
  • The figures here are illustrations at the assumptions you set above. They are not a projection, a track record or a promise.
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