$500/month at 8% becomes $472,000 in 25 years, and you only put in $150K. See the curve, side-by-side scenarios, and the inflation-adjusted real value.
A clean SIP projection with step-up, multi-scenario returns, and the inflation toggle most calculators leave out.
Plan against the conservative number. Use the optimistic case to celebrate.
Direct answers to the most common questions, in plain language. Skim if you're in a hurry; dig deeper below.
$472,000 at 10%, and you only contributed $150K.
Investing $500/month for 25 years at a 10% expected return grows to roughly $472,000. Of that, only $150,000 came from your contributions; the other $322,000 is compounded returns. The longer the horizon, the more dramatic the compounding share gets.
In flat or down markets, yes. In long bull runs, lump sum wins.
SIPs smooth out timing risk by averaging your buy price across months. Studies show lump sum beats SIP about two-thirds of the time historically, because markets rise more years than they fall. But SIPs are emotionally easier to maintain, and the consistency is what actually matters.
7–10% for equity, 4–6% for hybrid, 3–4% for debt.
For equity index funds, a 7–10% long-run return is a reasonable assumption (US S&P 500 has averaged ~10% historically). Hybrid funds usually deliver 5–7%; debt funds 3–5%. Always model both an optimistic and a conservative number, not just one.
Increase your monthly contribution annually, typically 10%.
A step-up SIP raises your monthly investment by a fixed percentage each year (usually 5–10%). Because your contributions grow with your income, the end corpus can be 60–90% larger than a flat SIP over a 25-year horizon. The earlier you start stepping up, the more it compounds.
The mechanics in short answers. No jargon, no upsell.
A SIP is a stream of small lump sums. Each one starts earning the same compound interest as the bigger ones; they're just earning it for less time. Early contributions compound longest, which is why starting young matters so much.
At year 5 of a SIP, your contributions still dominate the corpus. By year 15, returns start to overtake contributions. By year 25, your gains are 2–3× what you put in. The hockey-stick shape is the whole point.
$300/month for 30 years grows larger than $500/month for 20 years at the same return. Most investors flip these numbers in their head; the math doesn't. If you can't increase the amount, increase the horizon.
A 10% annual step-up on a $500 starting SIP, at 8% return over 25 years, ends up about 80% larger than a flat $500 SIP over the same period, without ever feeling like a stretch in any single year.
Worked example: $500 a month for 20 years at 8%: n = 240, r ≈ 0.00667; your $120,000 of contributions grows to ≈ $296,474, so gains make up more than half the final corpus.
We simulate month by month with contributions at the start of each month, applying any annual step-up exactly when it happens. Returns are assumed constant; real markets are not. Everything runs locally in your browser; your numbers never leave this page.
Designed so anyone can model their situation in under a minute, with or without a finance background.
Watch your contributions vs. the gains earned over time: month by month, year by year.
Add a 5–10% annual increase to your SIP and see how dramatically the final number grows.
Target $1M in 20 years? See exactly what monthly amount gets you there at your expected return.
See the real (post-inflation) value of your corpus: what it'll actually buy in 2050.
Run 6%, 8%, and 10% in parallel; don't bet your retirement on one assumption.
A clean calculator that just runs the math, locally in your browser.
Everything you might ask before, during, or after using this tool.
A Systematic Investment Plan (SIP) is an automatic, recurring investment, usually monthly, into a mutual fund or index fund. SIPs enforce discipline (you don't skip months because the market is scary), and they average your buy price across high and low periods.
No. SIPs only smooth out timing risk, not market risk. If your fund or asset class loses money over the long term, your SIP will too. That said, equity SIPs of 15+ years in major markets have rarely lost money historically; equity index SIPs in the US, India, and developed markets have all produced positive real returns over 15-year rolling windows.
A step-up SIP increases your contribution each year (typically 5–10%) automatically. It matches your income growth and dramatically boosts the final corpus. On a 25-year horizon, a 10% step-up can result in 60–90% more wealth than a flat SIP.
For most people: monthly. It's easier to maintain and lowers timing risk. If you have a windfall (bonus, inheritance), lump sum at the start mathematically beats SIP about two-thirds of the time over long horizons, but only if you can stomach an immediate drawdown right after investing.
No. SIP returns track the underlying fund's performance. A 10% historical return doesn't guarantee 10% going forward. Always model conservative cases and never bet money you need in less than 5 years on equity SIPs.
Two good reasons: (1) you've reached your goal corpus and want to lock in gains, or (2) your circumstances change and you genuinely can't afford it. A bad reason: the market dropped and you got scared. Markets falling is when SIPs work best: you buy more units at lower prices.
It varies by country. In the US, mutual fund gains held over a year are taxed at long-term capital gains rates (0–20%). For ETFs and index funds, taxes are deferred until you sell. In India, equity mutual funds have a 10% LTCG above ₹1.25 lakh per year after one year of holding.
Sort of. A SIP is a method (monthly contributions); an index fund is a type of asset (passive fund tracking a benchmark). You can SIP into an index fund, and that's typically the cheapest, lowest-risk way to do equity SIPs long-term. Active mutual funds are also commonly used but charge higher fees.
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Compound interest is famously called "the eighth wonder of the world," but most people don't actually feel it until they see a SIP corpus chart. For the first 5–7 years, your money in equity feels disappointing, barely above what you contributed. Then the curve bends. By year 15, your gains start matching your contributions. By year 25, they dwarf them.
This is why "starting early with a small amount" beats "starting late with a big amount" in almost every case. A 25-year-old investing $300/month at 8% retires with more than a 35-year-old investing $600/month at the same return. The math is unromantic, and it's also non-negotiable.
Academic studies repeatedly find that lump sum investing beats dollar-cost-averaging (SIP) about two-thirds of the time over long horizons. The reason is simple: markets rise more years than they fall, so getting all your money in earlier captures more time in the market.
But here's the asterisk: the studies assume you'll actually invest the lump sum. In the real world, people who plan to "lump sum next month" often delay, second-guess, and end up not investing at all. A SIP that you actually run beats a perfect lump sum strategy you never execute. Discipline > optimization.
A flat $500/month SIP feels like the same financial commitment in year 1 and year 20. But your income probably grows 3–6% a year over a career, so that flat SIP becomes a smaller and smaller share of your earnings. Step-up SIPs match the SIP to your income trajectory, which is a much more honest reflection of how you actually save.
A 10% annual step-up starting from $500/month, over 25 years at 8%, produces about $1.05M, vs. about $565K for the flat SIP. Same starting amount, same return, same time. The only difference is that you let the contribution scale with your income.
A SIP that grows to $1,000,000 in 25 years sounds great. But at 3% inflation, $1M in 2050 has the buying power of about $478K today. The "real" return on a 10% nominal SIP at 3% inflation is closer to 7%. This is why long-horizon plans should always be done in inflation-adjusted (real) terms.
When you set goals, think in today's dollars. "I need $5,000/month in retirement" is a 2026 number. In 2050 dollars, that's closer to $10,500/month. Most people undershoot retirement because they forget to inflate their target, a common mistake worth catching with a real-vs-nominal toggle in any calculator.
Two short notes worth reading before you trust any number on this page.
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