SIP Calculator (Systematic Investment Plan)

What This Calculator Really Does

A systematic investment plan (SIP) invests a fixed amount every month into a fund. This calculator projects the future value of those contributions using the annuity-due formula — each installment compounds from the month it is invested — and separates what you put in from what compounding added.

The honest caveat first: the calculator compounds at a constant assumed rate, while real market returns vary year to year. The output is a planning estimate for a given average return, not a promise. Run pessimistic, expected and optimistic rates to see the spread.

Everything runs locally in your browser: no amounts uploaded, nothing tracked, offline after the first visit.

The Formula, Explained Plainly

FV = P × [((1 + i)ⁿ − 1) ÷ i] × (1 + i)

• P — the monthly installment.
• i — the monthly rate: annual rate ÷ 12 ÷ 100 (12% → 0.01).
• n — the number of monthly installments.

The trailing (1 + i) marks the annuity-due convention: each payment invests at the start of its month, so it earns that month's return — the standard SIP assumption. Without it, the result understates by one month of growth.

How to Use It — In Order

1. Enter the monthly amount — what you plan to invest each month.
2. Enter the expected annual return — as a percentage; historical equity averages are not guarantees.
3. Enter the duration — in years or months; the tool converts.
4. Read invested vs gain — the split between contributions and compounding.
5. Run three rate scenarios — the difference between 10% and 14% over long horizons is enormous.
6. Extend the tenure once — add five years and watch how late-tenure growth accelerates; compounding is back-loaded.

Worked Example, Verified by Hand

₹5,000 per month, 12% annual, 5 years (i = 0.01, n = 60):

1. (1.01)⁶⁰ = 1.81670.
2. (1.81670 − 1) ÷ 0.01 = 81.670.
3. × 1.01 = 82.4866 (annuity-due factor).
4. × 5,000 = ₹4,12,433.
5. Invested: 5,000 × 60 = ₹3,00,000 → compounding added ≈ ₹1,12,433.

Extend to 10 years at the same rate: the factor roughly triples-plus, the corpus passes ₹11.6 lakh on ₹6 lakh invested — the last years contribute disproportionately.

Common Mistakes to Avoid

• Dividing the annual rate by 12 as a percentage-point slip — 12% ÷ 12 = 1% monthly, entered as 1, not 0.01 or 12.
• Comparing SIP projections across different assumed rates — the rate assumption dominates the answer.
• Treating the projection as a guarantee — market returns sequence differently every year; rupee-cost averaging smooths but does not fix that.
• Ignoring inflation — ₹41 lakh in 15 years buys what roughly ₹16–20 lakh does today at 5–6% inflation; use the inflation calculator for real values.
• Forgetting expense ratios and taxes — the assumed return is gross; fund costs and capital-gains tax reduce the realized figure.

Limitations

• Constant-rate compounding — real returns fluctuate; sequence risk is invisible here.
• No step-up modeling — the separate step-up SIP calculator handles annual contribution increases.
• No fees, taxes or exit loads — subtract those from your planning return.

Expected Accuracy

The annuity-due arithmetic is exact at full floating-point precision and matches a hand calculation to the rupee for the same rate and tenure. Realism depends entirely on the rate you assume.

Privacy — Your Data Never Leaves This Device

Investment figures stay in your browser: no account, no upload, no tracking — offline after first visit.

Related Tools & Guides

Natural next steps from SIP:

• All Finance Calculators
• Lump Sum vs SIP — the classic deployment question
• Step-Up SIP Calculator — rising contributions each year
• Compound Interest Calculator — the underlying math
• Guide: How SIP Returns Are Calculated

Sources & Standards

The annuity-due future-value formula is standard financial mathematics used across mutual-fund projections.

• AMFI (Association of Mutual Funds in India) — SIP context
• SEC Investor.gov — compounding fundamentals

Bottom Line

SIP math is an annuity-due: monthly rate, monthly compounding, start-of-month payments. Project with three rates, subtract inflation, and let tenure do the heavy lifting.

Frequently Asked Questions