₹5,000 a month sounds small until compounding multiplies it 19×: at 12% for 10 years, ₹6 lakh invested becomes ~₹11.5L. Stretch to 15 years and it nears ₹25L; to 20, past ₹49L. Time plus rate plus discipline — the three levers of every SIP projection. This guide runs the exact numbers for 10/15/20 years, adds the 10% step-up trick salaried investors swear by, and contrasts SIP with same-money lump sums so you pick deliberately.
Part of the India wealth & tax guide. Model it live in the SIP calculator (₹5k/10y/12% preset + step-up toggle); compare lump sums in compound interest.
10, 15, 20 years at 12%: the patience table
| Horizon | Invested | Maturity ≈ | Gains |
|---|---|---|---|
| 10 years | ₹6.0L | ₹11.5L | ₹5.5L |
| 15 years | ₹9.0L | ₹24.9L | ₹15.9L |
| 20 years | ₹12.0L | ₹49.9L | ₹37.9L |
Formula underneath: FV = M×(((1+mr)^n−1)/mr) with mr = 1% monthly, n = months. Notice gains overtake principal after year 7 — that crossover is compounding visibly working. Verify each row with the preset buttons, then test your own monthly figure.
Step-up 10%: salary growth becomes wealth growth
Flat ₹5,000 ignores raises. A 10% yearly step-up (₹5,000 → ₹5,500 → …) tracks typical salary growth and lifts 10-year maturity past ₹17L — roughly 50% more for money you barely miss because lifestyle never absorbed it. Automate the step-up at the same time as the SIP (April, with appraisals); manual annual increases die by February. Compare flat vs step-up side by side in the calculator before committing — the gap column sells the habit better than any lecture.
SIP vs lump sum on identical ₹6 lakh
Same ₹6L as a day-one lump sum at 12% for 10 years: ~₹18.6L — more than SIP's ₹11.5L, because every rupee compounds from day one. So why SIP? Because nobody holds idle ₹6L, and lump sums face entry-timing risk (deploy before a crash and sequence hurts). SIP's real edge is behavioral: automated, affordable, crash-agnostic (downturns buy more NAV units). Windfall rule: lump-sum money you already hold, SIP money you earn monthly. NAV and expense ratios explain projection gaps between calculators — same math, different fee assumptions (see compounding frequency).
Informational purposes only — not financial advice. Fixed-return illustrations; markets deliver sequences. See /terms.