How we actually calculate this
Most online calculators in India use a single, optimistic return number (often 15-18%) that makes outcomes look great. The reality is messier — and we'd rather show you that.
The data behind our reality checks
Our return-bracket messages are based on actual Nifty 50 historical data from 1991 to 2025:
SIP calculator math
AMFI/Groww-standard SIP formula: Future Value = P × ((1+r)n − 1)/r × (1+r), where P is the monthly SIP, n is months, and r is the effective monthly rate derived from the annual rate: r = (1 + annual)1/12 − 1. Using effective rate (not simple annual÷12) ensures the compounded annual return matches the user-entered rate exactly. Calculator matches Groww and AMFI to the rupee.
Step-up SIP math
Each year's contribution is calculated separately using the AMFI SIP formula, then compounded for the remaining years. Year-N's monthly SIP = initial × (1 + step-up%)N-1. Each year's accumulated value is then grown at the annual return rate for the remaining years until maturity.
Lumpsum calculator math
Standard annual compounding: Future Value = P × (1 + r)n, where P is the principal, r is the annual return rate, and n is the number of years. Matches the convention used by AMFI, Groww, and most Indian financial calculators.
SWP calculator math
Calculated month-by-month: corpus grows by monthly return rate, then monthly withdrawal is subtracted. Repeats until withdrawal period ends or corpus depletes (whichever comes first). The "withdrawal rate" shown is annual withdrawal as a percentage of the initial corpus — the global "4% rule" suggests rates above 4-6% may not be sustainable long-term.
Goal-based SIP math
Inverts the AMFI SIP formula to solve for monthly SIP: P = Goal / (((1+r)n − 1)/r × (1+r)). Uses the same monthly compounding and begin-of-month convention as the SIP calculator.
Inflation assumption
We use 6% as the long-term Indian inflation rate. India's CPI has averaged 5.5-6.5% over the past 20 years. Real returns are calculated using the Fisher equation: (1 + nominal) ÷ (1 + inflation) − 1.
Term insurance formula
Total cover needed = (Annual income × 15) + outstanding loans − existing investments. The 15× rule provides ~15 years of income replacement, accounting for inflation and your dependents' lifestyle. Premium estimates are illustrative ranges for a healthy 30-year-old non-smoker; actual premiums vary by age, health, lifestyle, and insurer.
Important caveats
Past performance is not indicative of future returns. These calculators are educational tools — not personalized financial advice. Real-world outcomes are affected by expense ratios (typically 0.5-2% per year), exit loads, taxes (LTCG 12.5% on equity gains above ₹1.25L/year), and behavioral factors like missed SIPs or panic-selling.
Last updated: May 2026. Data sources: niftyindices.com, AMFI fund performance data, RBI inflation reports.
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