SIP Calculator: See What Your Monthly SIP Becomes (With Step-Up and Inflation)

Most people put ₹10,000 a month, 20 years and 15% into a SIP calculator, see ₹1.52 crore and stop reading. I've done it myself, and I understand why. It's a lovely number. The trouble is what it leaves out. At 6% inflation, that ₹1.52 crore buys roughly what ₹47 lakh buys today, and 15% is an optimistic return to plan around.

A proper SIP calculator works out the future value of a fixed monthly investment at an assumed return. The result is only useful if the return you assume is honest, you add a yearly step-up, and you convert the final figure into today's rupees.

This guide works through each of those with real numbers. Along with that, it covers the direct vs regular plan math.

How a SIP calculator works

All SIP calculators, whether from a broker, an AMC or anyone else, use the same future-value formula:

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

Here, P = monthly SIP amount, i = expected annual return ÷ 12, n = number of months.

You enter three things: the monthly amount, the number of years and the expected return. You get back three numbers: amount invested, estimated returns and total value. The calculator only multiplies. The judgement lies in the return you choose, and that's where most people go wrong.

Ready reckoner: ₹10,000 a month at different returns

Look at the 20-year row. Moving from 10% to 14% changes the result by more than ₹55 lakh.

What return should you put in the SIP calculator?

These are the assumptions you can use:

• Large-cap or index fund: 10%. This one is deliberately conservative. If the actual return is higher, that's a bonus.
• Mid-cap fund: 12% as the base case. The Nifty Midcap 150 TRI, which is the benchmark most mid-cap funds track, returned 13.21% over 3 years and 13.49% over 5 years as of 12 October 2026, according to Upstox/ACE MF data. Assuming a bit less than that gives you some margin of safety.
• 14% only as your optimistic case. Look at it, but don't plan your life around it.

Why not use the 17–18% ten-year returns you see on fund ranking pages? Those numbers come from the funds that turned out to be winners. Your own fund may not end up on that list, and every investment period includes some bad years.

Step-up SIP calculator

A step-up SIP raises your monthly amount by a fixed percentage every year, usually around the time of your appraisal. Your salary won't stay flat for 20 years, so consider that in your SIP.

The math: ₹10,000/month, 20 years, 12% expected return. Flat SIP: you invest ₹24 lakh and end with about ₹99.9 lakh. 10% annual step-up (₹10,000 → ₹11,000 → ₹12,100...): you invest about ₹68.7 lakh and end with about ₹1.99 crore. The step-up roughly doubles the final corpus. Most of that gain comes from the extra money you put in, and compounding then works on a larger base.

To be fair about the trade-off, a 10% step-up means that by the 20th year, you're investing about ₹61,000 a month. That's manageable if your income grows.

If you're early in your career on ₹6–8 LPA, a 5% step-up is still much better than none.

SIP calculator with inflation

Calculators show you nominal rupees, but your future grocery bill won't be priced in today's rupees. Divide the final figure by (1 + inflation)^years to see what it's worth today. With 6% inflation over 20 years, that divisor is about 3.21.

₹31 lakh in today's money, built from ₹10,000 a month, is still a real result. It’s just that you should know the real worth of the returns.

Working backwards: how much SIP for ₹1 crore?

At an assumed 12% return, with no step-up:

• 20 years: about ₹10,000 a month
• 15 years: about ₹19,800 a month
• 10 years: about ₹43,000 a month

Every five years you delay, roughly doubles the monthly amount you need. That's the most important thing this calculator can show you.

Direct vs regular: the SIP math behind SEBI's 1 November 2026 change

At NDTV Profit IGNITE in Mumbai on 28 October 2026, SEBI Chairman Tuhin Kanta Pandey said that from 1 November, direct plans will be the default option on AMCs' digital platforms. Investors who choose regular plans must be told about their higher expense ratio (Business Today).

The change is now in effect. It sets the default selection on AMC websites and apps. Regular plans are still available, and nothing in it converts existing holdings.

Direct and regular plans hold the same portfolio and have the same fund manager. The only difference is the distributor's commission, which sits inside the TER (total expense ratio). If you'd like a refresher on how that fee is taken out, our expense ratio explainer covers it.

The math (illustrative, assuming a 1% TER gap)

₹10,000/month for 10 years: 12% gives about ₹23.2 lakh, 11% gives about ₹21.9 lakh. You lose ≈ ₹1.3 lakh. ₹10,000/month for 20 years: 12% gives about ₹99.9 lakh, 11% gives about ₹87.4 lakh. You lose ≈ ₹12.6 lakh.

Real TER gaps differ by scheme. Check the factsheet for your fund before deciding anything.

Watch out: Your existing regular-plan SIPs won't move to direct on their own. You can stop the regular SIP and start a direct one, and your old units stay invested. If you move existing units across, that counts as a redemption, so it can trigger capital gains tax and exit loads (Business Today). Before shifting a large amount, run the numbers on the tax.

Best mid cap mutual funds

Mid-cap funds invest mainly in companies ranked 101–250 by market capitalisation on AMFI's list. AMFI reviews that list every January and July.

The Nifty Midcap 150 TRI was down 6.49% over the three months to 12 October 2026 and roughly flat over a year, at 0.04%. Even so, investors put ₹7,834.84 crore into mid-cap funds in September 2026, up from ₹6,989.40 crore in August.

Monthly SIP contributions across all funds also hit a record ₹32,490 crore in the same month.

These are the six mid-cap funds with the highest 10-year returns on ACE MF's data (direct-plan returns as of 12 October 2026):

on 28 October 2026, SEBI Chairman Tuhin Kanta Pandey said that from 1 November, direct plans will be the default option on AMCs' digital platformsRegular-plan returns will be lower than these by roughly the TER gap. For HSBC Midcap, the 12 October 3-year figure works out to about 22.1% for the direct plan and 20.8% for the regular plan, as per NAV data from HSBC Mutual Fund's fund centre.

The order of this list changes depending on which period you look at. The 1-year leader and the 10-year leader aren't the same fund. So, judge a mid-cap fund on consistency, not on last year's number. Our guide to rolling returns shows how to do that.

Thumb rule for mid-cap SIPs: only start one if you won't need the money for at least 7 years. A 7+ year horizon means a falling market is just your SIP buying more units at lower prices. A 3-year horizon means you may have to sell at a loss. Either way, use 12% in the calculator, not the 18% in the table.

Don't fund your SIP with credit card debt

Paying for SIPs on your credit card, through a workaround app or by letting the card bill revolve so cash is free for the SIP, is a bad trade. Revolving credit card interest usually runs at 3–4% a month, which is 36–48% a year.

Carrying ₹10,000 at 3.5% a month costs ₹350 a month, about 42% a year, while the SIP is expected to make perhaps 12%. You're paying more than three times what you hope to earn. Our credit card interest rate guide has the full breakdown.

The same reasoning applies to safety. If you don't yet have an emergency fund, build that before you start a mid-cap SIP. If your first emergency ends up on a credit card at 42%, it wipes out years of 12% returns.

So, what should you put in the calculator?

If you’re setting up a SIP this week, you can go with the direct plan. Turn on a 10% annual step-up, or 5% if money is tight. Use 12% for mid-caps and 10% for large-caps, and divide the result by the inflation factor before you decide whether it's enough.

If ₹10,000 a month with a step-up gets you to roughly ₹62 lakh in today's money over 20 years, and that meets your goal, you have a plan. If it doesn't, raise the monthly amount or start sooner. Hoping for 15% isn't a plan.

You know your income, your goals and how well you sleep when markets fall. Use the numbers, then make the call. More practical money guides are on the Monzy blog.

FAQs about SIP calculator

Are SIP calculator results guaranteed?

No. A SIP calculator applies a fixed return to every year, while real markets go up and down. Mid-cap funds, for example, were roughly flat over one year as of October 2026. Treat the result as an estimate that depends on your return assumption. Use a conservative rate, such as 10% for large-caps and 12% for mid-caps, and compare it with an optimistic case.

How much SIP do I need for ₹1 crore?

Assuming a 12% annual return and no step-up, you need about ₹10,000 a month for 20 years, about ₹19,800 a month for 15 years, or about ₹43,000 a month for 10 years. A yearly step-up brings the starting amount down considerably. Keep in mind that ₹1 crore in 20 years is worth only around ₹31 lakh in today's money at 6% inflation.

What is a step-up SIP and is it worth it?

A step-up SIP raises your monthly investment by a fixed percentage each year, usually in line with salary hikes. Over 20 years at an assumed 12%, a ₹10,000 SIP with a 10% annual step-up grows to about ₹1.99 crore, compared with about ₹99.9 lakh for a flat SIP. Most of that difference comes from the extra money you invest, so set a step-up percentage you can actually keep up.

Will my regular SIP switch to a direct plan automatically after 1 November 2026?

No. SEBI Chairman Tuhin Kanta Pandey said on 28 October 2026 that direct plans become the default on AMC digital platforms from 1 November. That’s for new investments; existing holdings aren't converted. You can stop the regular SIP and start a direct one. Moving existing units counts as a redemption, though, and may attract capital gains tax and exit loads.

Should I stop my mid-cap SIP when mid-caps are falling?

If your horizon is at least seven years, a falling market means your SIP is buying more units at lower prices, which is how SIPs are meant to work. Investors put ₹7,834.84 crore into mid-cap funds in September 2026 despite weak returns. If you need the money within two or three years, mid-caps were probably the wrong choice for that goal to begin with.

Can I pay for my SIP with a credit card?

Even when a workaround exists, you should avoid it. If the card bill revolves, interest of 3–4% a month (36–48% a year) far outweighs the roughly 12% a SIP might earn. A better approach is to run the SIP from your bank account by mandate on salary day, use your card for normal spending, pay the bill in full, and add the cashback to your SIP.

Disclaimer

Mutual fund investments are subject to market risks. Read all scheme-related documents carefully.

This is my honest read, not formal financial advice. I'm not your advisor, and before you act on anything big you should run it past a professional. Returns shown are estimates, not guarantees, and naming a fund here isn't a recommendation to buy it. That said, this is exactly how I'd think it through.