What is the exact formula used by Indian Mutual Fund SIP calculators?

Indian SIP calculators use the annuity-due future value formula: FV = P * [((1 + i)^n - 1) / i] * (1 + i), where P is monthly SIP, i is annual rate divided by 12, and n is total months.

How is SIP maturity taxed in India for FY 2025-26?

Under Section 112A, Long-Term Capital Gains (LTCG) on equity mutual funds held for more than 12 months are exempt up to Rs 1.25 Lakh per financial year. Gains above Rs 1.25 Lakh are taxed at 12.5% plus 4% cess.

How does a 10% annual Step-Up SIP affect my final corpus?

Increasing your monthly SIP contribution by 10% every year in line with salary increments can more than double your 20-year maturity corpus compared to a flat SIP.

SIP Calculator India (FY 2025-26) — Step-Up, Inflation & LTCG Tax

Monthly Investment (P)

₹

Expected Return Rate (p.a.)

Investment Horizon

Yrs

Annual Step-Up SIP (Top-Up)

Increase monthly SIP every year with salary hikes

Adjust for 6% Annual Inflation

Discount final corpus into today's purchasing power

Expected Maturity Corpus

₹1.26 Cr

₹1,26,14,400 • Growth Multiple: 2.80x

Total Invested

₹45.00 L

₹45,00,000

Est. Wealth Gains

₹81.14 L

₹81,14,400

Post-LTCG Corpus

₹1.16 Cr

Tax: ₹9.99 L (12.5% > ₹1.25L)

Principal vs Compounding Split

Hockey-Stick Growth Curve Gold: Corpus | Dashed: Invested

⚡ Power of Starting Early (Cost of a 3-Year Delay)

If you delay starting this SIP by just 3 years (investing for 12 years instead of 15), your final corpus drops to ₹80.57 L — costing you ₹45.58 L in lost compounding for saving just ₹9.00 L of contributions.

📋 FY 2025-26 Section 112A Equity LTCG Tax Note

If redeemed in a single financial year after 12+ months, the first ₹1,25,000 of capital gains is tax-exempt. Gains above ₹1.25 Lakh attract 12.5% LTCG tax (₹9,98,675 base tax before 4% health & education cess).

Year-Wise SIP Cashflow & Compounding Schedule

Watch when your annual compounding gains overtake your cumulative pocket contributions.

Year	Monthly SIP	Cumulative Invested	Wealth Gained	Year-End Corpus	Today's Value (6% Infl.)

How the SIP Formula Works (With Worked Example)

Unlike lump-sum investments where your entire capital compounds for the full tenure, a Systematic Investment Plan (SIP) deploys fresh cash every month. Because each SIP installment is invested at the beginning of the month, Indian AMCs and AMFI standard calculators use the Annuity-Due Future Value Formula:

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

P = Monthly SIP installment (e.g., ₹25,000)
i = Periodic monthly rate = Annual Rate / 12 / 100 (e.g., 12% / 12 = 0.01)
n = Total number of installments = Years × 12 (e.g., 15 × 12 = 180)

Step-by-Step Worked Example

For P = ₹25,000, Annual Rate = 12% (so i = 0.01), and Tenure = 15 Years (n = 180):

1. (1 + 0.01)¹⁸⁰ = 5.995802
2. (5.995802 − 1) / 0.01 = 499.5802
3. FV = 25,000 × 499.5802 × 1.01 = ₹1,26,14,400 (₹1.26 Cr)

Practical SIP Strategies for Indian Investors

1. Use the 10% Annual Step-Up Rule

A static ₹25,000 SIP over 15 years at 12% grows to ₹1.26 Crore. If you activate a modest 10% annual step-up as your income rises, the exact same starting SIP compounds to ₹2.17 Crore—adding ₹91 Lakh of extra wealth.

2. Tax-Gain Harvesting Under Section 112A

Since ₹1.25 Lakh of long-term equity capital gains is tax-free every financial year, long-term investors often redeem and immediately re-invest units held over 12 months each March to reset their purchase NAV and legally lower future LTCG liability.

3. Never Stop SIPs During Market Corrections

Rupee Cost Averaging works best when Nifty falls 10–20%: your fixed monthly rupee amount buys significantly more mutual fund units at lower NAVs, turbocharging your recovery multiple.

Frequently Asked Questions (SIP)

Across the Indian mutual fund industry (AMFI, Groww, Zerodha Coin, and SEBI illustrations), nominal annual return is converted to monthly periodic return via i = r / 12 using the annuity-due formula FV = P × [((1+i)^n - 1)/i] × (1+i). We use this exact convention so your numbers match industry benchmarks to the rupee.

In a SIP, each monthly installment is treated as a separate purchase on a First-In-First-Out (FIFO) basis. Units held for more than 12 months in equity-oriented funds (>65% Indian equity) qualify for Long-Term Capital Gains under Section 112A: the first ₹1.25 Lakh of gain in a financial year is tax-free, and remaining gains are taxed at 12.5%.

Over rolling 10-to-15 year periods in India, Nifty 50 TRI has historically compounded around 11.5%–12.5% p.a., diversified Flexi-Cap funds around 13.5%–14.5% p.a., and Small-Cap funds higher with significantly higher interim drawdowns. For conservative goal planning, 12% is the gold standard.

₹1 Crore twenty years from now will not buy what ₹1 Crore buys today. Discounting your nominal maturity value by 6% annual CPI inflation shows you the real purchasing power of your corpus in today's rupees.

Yes. Mutual fund SIPs are completely flexible. AMCs do not levy penalties for pausing, stopping, or changing your SIP mandate, though standard fund exit loads (usually 1% if redeemed within 1 year) still apply to recent installments.

Long-term backtests on Nifty 50 over 20 years show less than a 0.15% CAGR difference between daily, weekly, and monthly SIPs. A monthly SIP scheduled 2–3 days after your salary credit date is the simplest and most sustainable choice.