Data & Methodology

All Net Asset Value (NAV) data displayed on fundsipcalculator.com is sourced from the following public APIs:

• Association of Mutual Funds in India (AMFI): The primary source for daily NAV data of all registered Indian mutual fund schemes. AMFI publishes NAV data at the end of each business day.
• BSE India: Supplementary source used for cross-verification and historical NAV data that may not be available through the AMFI API.
• Morningstar India (historical): Used for back-filling historical NAV data for certain fund schemes where primary sources have data gaps.

Our fund database covers 3,000+ active mutual fund schemes across all categories — equity, debt, hybrid, index, ELSS, and sectoral funds — spanning direct and regular plans. This count includes direct and regular plan options. We update the database continuously as new schemes launch and existing schemes add NAV history.

NAV data updates follow this schedule:

• Daily NAV (latest): Fetched from AMFI at the end of each business day. Latest NAV is typically available by 9:00 PM IST on business days.
• Historical NAV (past 1 year): Updated weekly to ensure recent data is complete and accurate.
• Full historical data (all available): Refreshed on a rolling monthly basis. For most funds, data extends back to the fund's inception or to 2006-2008 for older schemes.

NAV data may occasionally have gaps due to:

• Public API downtime or rate limiting
• Non-business days (weekends, public holidays)
• Fund-level events (mergers, schemes closed to new subscriptions)

When data gaps are detected, the calculator interpolates returns over the available data range and flags the actual start/end dates used in the results display.

Our SIP calculation simulates actual unit accumulation month by month:

1. Fund selection: User searches and selects any mutual fund from our database of 3,000+ active schemes (including direct/regular plan options).
2. Date range: User selects a start date and end date. The system validates that both dates fall within the fund's available NAV history. If the fund lacks data at either boundary, the closest available NAV dates are used and displayed.
3. Investment schedule: For each month in the range, the system identifies the NAV on the investment date (same day of month as the start date, or the next available business day if that day is a non-business day or has no NAV data).
4. Unit accumulation: Units purchased = Monthly Investment Amount / NAV on Investment Date. Units accumulate with each monthly investment.
5. Final portfolio value: Portfolio Value = Total Units Accumulated × NAV on End Date.
6. Total invested: Monthly Amount × Number of Successful Investments (months where NAV data was available).
7. Total returns: Portfolio Value - Total Invested.

XIRR is the correct metric for measuring SIP returns because it accounts for the timing of each individual cash flow. Unlike CAGR (which assumes all money is invested for the entire period), XIRR recognises that your first SIP installment compounds longer than your last installment.

Mathematical Definition

XIRR is the rate r that satisfies:

Where:

• CashFlow_i = Each monthly SIP contribution (negative value) and the final redemption amount (positive value)
• Date_i = The date of each cash flow
• Date₀ = The date of the first cash flow
• r = The annualised return (XIRR) being solved for

Implementation Details

• We use the Newton-Raphson method to solve the XIRR equation iteratively, with an initial guess of 10%.
• Convergence threshold: The algorithm stops when the NPV is within ±₹0.01 of zero, or after 100 iterations.
• Edge cases: If the investment period is less than 30 days, XIRR is not meaningful and is displayed as "N/A". If returns are negative, XIRR correctly reflects the negative annualised return.
• Accuracy: XIRR is rounded to one decimal place for display (e.g., 14.2%), but stored at higher precision for export calculations.

The lumpsum calculation is simpler than SIP:

1. Units Purchased = Lumpsum Amount / NAV on Start Date
2. Portfolio Value = Units Purchased × NAV on End Date
3. CAGR = (Portfolio Value / Invested Amount)(1 / Years) - 1

CAGR (Compound Annual Growth Rate) is used for lumpsum returns instead of XIRR, since there is only one investment date and one redemption date.

Our step-up SIP feature models increasing your investment amount annually:

• Base amount: Monthly investment in year 1.
• Annual increment: User-specified percentage increase each year (default 10%).
• Calculation: Year 1: ₹10,000/month. Year 2: ₹11,000/month (10% step-up). Year 3: ₹12,100/month. And so on.
• NAV assignment: Each month's installment still uses that month's actual NAV for unit accumulation.

Step-up SIP typically generates 2-3x higher final corpus compared to a fixed SIP over 20+ year periods, because the increasing contributions compound for longer.

Goal mode answers the question: "How much should I invest monthly to reach a target corpus?"

The calculation uses the future value of an annuity due formula:

Where:

• FV = Target corpus (user-specified)
• P = Required monthly SIP (what we solve for)
• r = Monthly return rate (annual return / 12)
• n = Number of months in the investment period

Rearranged to solve for P:

Note: Goal mode uses an assumed return rate (user-specified) since it projects into the future where NAV data does not yet exist. For historical analysis, use SIP mode with a real fund and date range.

All exports are generated entirely in your browser using these libraries:

• PDF: jsPDF with jsPDF-AutoTable plugin. Generates a branded report with fund name, period, investment summary, year-wise or month-wise breakdown table, and disclaimer. Font: Helvetica (standard PDF font).
• Excel (XLSX): SheetJS (xlsx library). Outputs an .xlsx workbook with a Summary sheet and a Yearly/Monthly breakdown sheet. All numbers use INR lakh/crore formatting.
• DOCX: Built using the docx library. Produces a formatted Word document with headers, tables, and the standard disclaimer.
• Image (PNG): Uses html2canvas to capture the results section as a high-resolution (2x) PNG image. Suitable for sharing on WhatsApp, X/Twitter, and Telegram.

Privacy guarantee: No data is uploaded to any server during export generation. All processing happens client-side in your browser using JavaScript. Your investment data, fund selections, and results never leave your device.

• NAV data gaps: Some funds have intermittent NAV data, particularly for very old dates or during fund mergers. When data is missing, the calculator issues a warning and uses the nearest available NAV date.
• Expense ratios: Our calculations use reported NAV, which is post-expense. The impact of expense ratios is already reflected in the NAV — we do not deduct additional fees.
• Exit loads: Not deducted from results. Exit loads (typically 1% for redemptions within 3-12 months, zero beyond that) are fund-specific and time-dependent. We display a note advising users to check fund-specific exit load terms.
• Taxes: Not deducted. LTCG (10% above ₹1L/year) and STCG (15% for equity, slab rate for debt) are not factored into displayed returns. Returns shown are pre-tax.
• Dividends: Our calculation assumes growth option (no dividend payouts). For dividend option funds, the NAV drops on ex-dividend dates, which is reflected in the data, but we do not model dividend reinvestment separately.
• Fund mergers & scheme changes: When a fund merges or undergoes a scheme change, historical NAV data may reflect the pre-merger entity's performance. We source data from the most recent surviving scheme's history.
• International funds: NAV for fund-of-funds investing in international securities may be delayed by 1-2 days due to time zone differences in underlying markets.