Somewhere between "I'll just check the fund's app" and "I'll build a spreadsheet with five years of NAV data," most SIP investors land on a method for comparing funds — often without ever weighing whether that method is actually reliable. Some people eyeball returns on a fund house's website. Some export NAV history into Excel and try to calculate XIRR themselves. Others just use a dedicated compare mutual funds tool and trust the output.

Each approach has trade-offs. Here's an honest look at what each one actually gets you — and where it quietly falls short.

Method 1: Comparing Funds by Eye on Fund Pages

This is the most common approach, mainly because it's the path of least resistance. You open two or three fund pages, glance at the "returns" section, and pick whichever number looks biggest.

What this gets right: It's fast, and it does at least surface the fund's headline numbers.

Where it falls apart: Every fund page presents returns differently — some show 1-year, some show since-inception, some show CAGR, some show absolute returns. You end up comparing numbers that aren't actually measuring the same thing. Worse, none of these figures account for how a SIP (as opposed to a lump sum) would have actually performed in that fund. A fund's "returns since inception" figure is close to irrelevant if you're about to start a monthly SIP — your money isn't going in as one lump sum on day one, so that number simply doesn't describe your situation.

Verdict: Fine for a first filter to narrow 20 funds down to 5. Not reliable enough to make a final decision.

Method 2: Building Your Own Spreadsheet

This is the approach of investors who take the decision seriously but don't yet have access to (or trust) a comparison tool. You pull historical NAV data, plug in your intended SIP amount and frequency, and try to calculate XIRR manually using a function like Excel's XIRR formula.

What this gets right: Done correctly, this actually produces an accurate XIRR — arguably the single most important number in a real SIP return comparison. It also forces you to engage with the data directly, which builds genuine understanding of how the fund behaved.

Where it falls apart: It's slow, and small errors compound quickly. Getting NAV history for multiple funds, aligning dates correctly, structuring the cash flows properly for the XIRR formula, and then repeating this for every fund you want to compare is a multi-hour task done properly — and most people rush it, introducing errors they never catch. It also doesn't naturally give you consistency scores or downside-resilience metrics; you'd need to build those calculations separately, and most people don't bother, so they end up with an accurate XIRR but no view of how stable that return actually was.

Verdict: More rigorous than eyeballing fund pages, but the time cost and error risk mean very few investors actually maintain this consistently, especially when they want to compare across categories or revisit the comparison periodically.

Method 3: Using a Dedicated Compare Mutual Funds Tool

A purpose-built comparison tool is designed to solve exactly the two problems above: the inconsistency of manually reading fund pages, and the time cost of building your own XIRR calculations from scratch.

What this gets right: You select the funds you want to compare — even across categories like large-cap, mid-cap, flexi-cap, or hybrid — set your actual SIP frequency, instalment amount, and duration, and the tool computes XIRR, wealth created, and a consistency score for each fund side by side. This removes both the ambiguity of mismatched return metrics and the manual effort of calculating XIRR yourself, while adding metrics — like consistency and downside resilience — that most people wouldn't calculate on their own even if they had the time.

Where it still requires judgment from you: A tool can compute the numbers accurately, but it can't decide your risk appetite or time horizon for you. If a fund shows a slightly lower XIRR but a much higher consistency score, whether that trade-off is right for you depends on your own goals — a fund tool gives you the inputs for that decision, not the decision itself.

Verdict: The most efficient and accurate way to run a genuine SIP return comparison, provided you still apply your own judgment about which trade-offs matter for your specific plan.

So Which Should You Use?

In practice, the three methods aren't mutually exclusive — they work well as a funnel. Use quick fund-page browsing to shortlist a handful of candidates from a wider universe. Then run those shortlisted funds through a proper compare mutual funds tool to get accurate, SIP-specific XIRR, consistency, and wealth-created figures. Reserve manual spreadsheet building for situations where you want to sanity-check a tool's output or explore a scenario the tool doesn't directly support — not as your primary method, since the time cost rarely justifies it for routine comparisons.

The Real Lesson

The method you use to compare mutual funds matters almost as much as the decision itself. Comparing by eye gives you speed but sacrifices accuracy. Manual spreadsheets give you accuracy but cost you hours you'll likely not repeat consistently. A dedicated comparison tool gives you both speed and accuracy, calculated specifically around your real SIP plan — which is exactly the combination a long-term SIP investor actually needs. Whichever method you lean on, the underlying principle stays the same: don't let convenience decide which numbers you trust.