SIP Calculator (Step-Up + Inflation + LTCG)

What this SIP calculator does

This is a full-featured Systematic Investment Plan calculator built for FY 2026-27. Unlike basic SIP tools, it supports:

• Step-up SIP — raise your monthly contribution by a fixed % each year.
• Lump-sum top-up — add a one-time investment at the start.
• Inflation adjustment — see real purchasing power, not just nominal corpus.
• Post-tax corpus — applies LTCG @ 12.5% with ₹1.25L exemption (Budget 2024).
• Year-wise growth table — invested vs corpus for every year.

The SIP formula

For a flat monthly SIP, future value (annuity-due) is:

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

• P = monthly SIP amount
• i = monthly rate = (annual return %) ÷ 12 ÷ 100
• n = total months = years × 12

For step-up SIPs we compute year-by-year: each year the SIP amount increases, and each previous year's closing balance compounds at the annual rate.

Worked example

₹10,000/month SIP, 12% expected return, 20 years, 10% annual step-up, 6% inflation:

• Total invested ≈ ₹68.7 lakh
• Nominal corpus ≈ ₹2.21 crore
• Inflation-adjusted (real) ≈ ₹68.9 lakh
• Post-tax corpus (LTCG 12.5%) ≈ ₹2.02 crore

Equity SIP taxation (FY 2026-27)

Per Budget 2024, gains on equity mutual funds held over 12 months are Long-Term Capital Gains taxed at 12.5% (without indexation), with an annual exemption of ₹1,25,000. Short-term gains (under 12 months) are taxed at 20%. Debt funds bought after 1 Apr 2023 are taxed at slab rate regardless of holding.

Tips to maximise SIP returns

• Start early — a 25-year-old needs ₹5,000/month at 12% to reach ₹1cr by 60. A 35-year-old needs ₹17,000/month for the same goal.
• Step-up annually — even a 10% step-up doubles the impact of a flat SIP over 20+ years.
• Stay invested — equity SIP returns over 15+ years almost always beat 11% CAGR; under 5 years they are unpredictable.
• Don't time the market — pause SIPs only on a fundamental life change, not on market dips.