Every formula, every assumption

Last reviewed: October 2026

This page covers two kinds of numbers. The calculators project the future from a return you choose. The fund pages and comparisons replay the past on actual NAVs. Both are below.

Calculators: the monthly rate

For an annual expected return r, we use the geometric monthly rate:

Many calculators use the simpler r / 12. That shortcut compounds to more than the stated annual return over a year and inflates the maturity figure. We deliberately use the correct geometric rate, which is why our headline number is usually a little lower than other tools — and more accurate.

The projection

We iterate month by month rather than use a closed-form annuity formula, so step-ups, contribution frequency and (in the XIRR tool) irregular flows all compound correctly:

Tax

For equity funds we apply the 2024–25 long-term capital gains regime: 12.5% on gains above ₹1,25,000 per financial year. The calculators show the tax deducted as its own line so nothing is hidden. Debt-fund and short-term treatment differ; where relevant the tool notes its assumption.

Inflation / real value

Real value discounts the post-tax corpus back to today's purchasing power:

Goal solver

Given a target, we bisection-search the base monthly SIP whose post-tax projection equals the target (post-tax corpus is monotonic in contribution, so bisection converges quickly). If you mark the target as "today's money", we first inflate it to its future nominal value.

XIRR

XIRR is the rate that sets the net present value of all dated cashflows to zero. We solve it with Newton–Raphson and fall back to bisection over a wide bracket when Newton diverges (irregular flows can cause that), using an actual/365 day count.

Fund pages: historical SIPs on real NAVs

The fund pages, category pages and fund comparisons don't assume any return. They replay a monthly SIP on each fund's actual history.

Data

• Source: the official daily NAVs published by AMFI (Association of Mutual Funds in India) — the latest-NAV file and AMFI's NAV history report. No third-party data aggregators.
• Option: Growth option only (IDCW/dividend NAVs fall when a payout is made, which would understate returns).
• History: from April 2006, where AMFI's history report begins. Direct plans exist only from January 2013.
• Updates: monthly, after the first week, so each month's instalment NAV is final. Every page states the NAV date it was valued at.
• Cleaning: if a fund's monthly NAV series has a gap of more than 45 days, or jumps by more than 2.5× (or falls below 0.4×) from one month to the next — signs of a merger or a change in unit face value — we drop the history before that point rather than guess.

How a SIP is simulated

Stamp duty (0.005% of each purchase) and exit loads are ignored; both are small for a long-held SIP. Returns are XIRR on the actual instalment dates, using the same Newton–Raphson solver as the calculators.

• “Last N years” means the most recent N×12 monthly instalments, valued at the latest NAV.
• Rolling returns test every possible N-year SIP in the fund's history: instalments in months s to s+N×12−1, valued at the NAV one month after the last instalment. We report the worst, median and best XIRR, the share that lost money, and the share that beat 6% a year.
• Real XIRR in the fund calculator is (1 + XIRR) ÷ (1 + inflation) − 1, with the inflation rate you choose.

Tax on the fund pages

“Post-tax” assumes you redeem the whole holding on the valuation date and have no other capital gains that financial year. Each instalment is taxed as its own lot, under the rules in force since 23 July 2024:

• Units held more than 12 months: long-term capital gains, 12.5% on net gains above ₹1,25,000.
• Units held 12 months or less: short-term capital gains at 20%.
• A net short-term loss is set off against long-term gains; a net long-term loss is not carried anywhere.
• Grandfathering (Section 112A): for units bought before 1 February 2018, the cost used is the higher of what you paid and the lower of the 31 January 2018 NAV and the sale value. We use AMFI's NAV on or just before 31 January 2018.
• ELSS units are locked in for three years from each instalment, so recent instalments couldn't actually be redeemed today; ELSS pages say so.

Which funds are covered

Only funds taxed as equity, so the tax maths above is correct for every page: open-ended equity schemes (all SEBI equity categories), aggressive hybrid funds, balanced advantage / dynamic asset allocation funds, and equity index funds. We leave out debt, gold and silver index funds, other hybrid categories, ETFs, fund-of-funds and international funds (funds that invest mainly abroad aren't taxed as equity in India). A fund needs at least three years of monthly NAVs to get a page, and funds with no NAV in the last 30 days are treated as closed. Direct and Regular plans of the same scheme are shown together on one page.

Category tables

Funds are ordered by the XIRR of the same monthly SIP over the same last five years, so every fund is measured on identical dates; funds with less history are listed last. Rolling columns cover each fund's own history, so they aren't comparable between funds that started at different times. The order is a historical fact, not a recommendation.

“Did it beat a plain index fund?”

Each active equity fund is compared with an index fund matched to its category — the simple alternative an investor could have bought instead. The index fund's NAV already includes its expense ratio and tracking error, so the comparison reflects what you would actually have earned.

• We chose the index fund with the longest history on each index. It may differ from a fund's official benchmark (for example, large cap funds are often benchmarked to the Nifty 100); the question we answer is whether the fund beat a plain index fund you could have bought, not whether it beat its own benchmark.
• Both funds are compared on identical dates, Direct plan against Direct plan where both exist, over every rolling 3- and 5-year SIP that falls in months where both have NAVs.
• The headline uses 5-year SIPs when they span at least three years of start dates, otherwise 3-year SIPs. Gap = fund XIRR minus index fund XIRR, in percentage points a year.
• Because the mid cap, small cap and Nifty 500 index funds only launched in October 2019, those comparisons cover a shorter, specific period, and each page states the dates tested.
• Hybrid funds and index funds themselves are not compared.

Fund-vs-fund comparisons

Comparison pages pair funds in the same SEBI category from the larger fund houses, each with at least five years of NAVs. Both funds get the same SIP on identical dates, Direct against Direct where both exist. We report the value and XIRR over the last 1, 3, 5 and 10 years, every rolling SIP head to head, and the downside on those same dates (worst SIP and how many lost money). A comparison shows what happened; it doesn't say which fund to buy.

Rolling returns of indices

The rolling returns calculator measures the annualised lump-sum return (CAGR) of every window of a given length, one window starting each month, using the first NAV of each month. Index levels come from index funds tracking each index — UTI Nifty 50, HDFC BSE Sensex and ICICI Prudential Nifty Next 50 (Regular plans, which have the longest history), and Motilal Oswal Nifty 500, Midcap 150 and Smallcap 250 (from October 2019). Returns are therefore after each index fund's costs, slightly below the total-return index.

Tax harvesting calculator

The tax harvesting calculator rebuilds your holding lot by lot: each SIP instalment buys units at the first AMFI NAV of its month, one-off purchases likewise, and redemptions you enter remove units first-in-first-out. On today's NAV, a lot is long-term if held more than 365 days and, for ELSS, sellable only from the third anniversary of its purchase. Gains use Section 112A grandfathering for units bought before 1 February 2018. Because redemptions always take the oldest units, harvestable units are the unbroken run of long-term, unlocked lots from the oldest end. The tax-free room is ₹1,25,000 minus long-term gains already booked this financial year (from redemptions you enter, plus the amount you type in). The plan books gains up to that room, starting with the funds that give the most gain per rupee redeemed, and rounds units to three decimals. Everything runs in your browser.

Survivorship bias

AMFI's current list only includes funds that still exist. Funds that were merged or closed — often the weaker performers — drop out, so they can't appear on a fund page or in a comparison. This makes active funds as a group look better than the full record would. We can't correct for it with AMFI's current data, so we state it instead.

Limitations

• Projections assume a constant return; real markets are volatile. These are estimates, not forecasts.
• Fund pages are history, not prediction. A fund's past SIP returns — including how it did against an index fund or another fund — do not indicate future returns.
• Tax rules change and depend on your circumstances. We state the regime and date; verify against current law.
• This site does not sell funds and is not investment advice. Consult a SEBI-registered adviser.

Sources

• Income Tax Act provisions on capital gains (Finance Act 2024).
• AMFI / SEBI mutual fund investor materials.
• AMFI daily NAV data (latest NAVs and NAV history report), portal.amfiindia.com.
• Section 112A of the Income Tax Act (long-term gains on equity-oriented funds, including the 31 January 2018 grandfathering rule), as amended by the Finance (No. 2) Act 2024.
• SEBI circular on categorisation and rationalisation of mutual fund schemes (October 2017).