SIP calculator with inflation

A ₹5,000 monthly SIP at 12% for 20 years reaches ₹49,95,740 on paper — but at 6% inflation that buys what ₹15,57,695 buys today. This calculator shows both numbers side by side, plus the real return rate that decides whether you actually got richer.

By Sudarshan Babar · Software engineer and founder of the getinfotoyou tool network Updated

Your SIP, and the inflation you expect

₹500₹1 lakh

What leaves your bank account every month. Type any amount — the slider is just a shortcut.

%
1%25%

An assumption, not a promise. Equity funds are usually modelled at 10–12%; see what rate to assume.

years
1 year40 years
%
0%12%

Set 0 to switch the "today’s money" column off. India’s CPI has averaged close to 6% over the past decade; the RBI targets 4% with a 2-point band.

Nominal against real

Total you put in ₹12,00,000
Corpus on paper ₹49,95,740
Eaten by inflation ₹34,38,044
Purchasing power retained 31.2%
Real return, a year 5.66%
Worth in today’s money ₹15,57,695
₹0₹12.5 L₹25 L₹37.5 L₹50 L036912151820

What you investNominal valueValue in today’s money

Real value = nominal ÷ (1 + inflation)^years.
Nominal value against value in today’s money, at 6% inflation.
YearMonthlyInvested so farReturnsValue at year endIn today’s money
1₹5,000₹60,000₹4,047₹64,047₹60,421
2₹5,000₹1,20,000₹16,216₹1,36,216₹1,21,232
3₹5,000₹1,80,000₹37,538₹2,17,538₹1,82,649
4₹5,000₹2,40,000₹69,174₹3,09,174₹2,44,895
5₹5,000₹3,00,000₹1,12,432₹4,12,432₹3,08,193
6₹5,000₹3,60,000₹1,68,785₹5,28,785₹3,72,773
7₹5,000₹4,20,000₹2,39,895₹6,59,895₹4,38,868
8₹5,000₹4,80,000₹3,27,633₹8,07,633₹5,06,719
9₹5,000₹5,40,000₹4,34,108₹9,74,108₹5,76,573
10₹5,000₹6,00,000₹5,61,695₹11,61,695₹6,48,685
11₹5,000₹6,60,000₹7,13,074₹13,73,074₹7,23,318
12₹5,000₹7,20,000₹8,91,261₹16,11,261₹8,00,747
13₹5,000₹7,80,000₹10,99,656₹18,79,656₹8,81,256
14₹5,000₹8,40,000₹13,42,090₹21,82,090₹9,65,140
15₹5,000₹9,00,000₹16,22,880₹25,22,880₹10,52,710
16₹5,000₹9,60,000₹19,46,891₹29,06,891₹11,44,287
17₹5,000₹10,20,000₹23,19,604₹33,39,604₹12,40,210
18₹5,000₹10,80,000₹27,47,196₹38,27,196₹13,40,834
19₹5,000₹11,40,000₹32,36,627₹43,76,627₹14,46,532
20₹5,000₹12,00,000₹37,95,740₹49,95,740₹15,57,695

Why the paper number misleads

Every SIP projection you have ever seen is in future rupees. That is not wrong, it is just not the number you can spend. A corpus is only useful measured against what things will cost when you get there.

The conversion is simple division: real = nominal ÷ (1 + i)years. At 6% inflation, dividing by 1.0620 knocks a corpus down to roughly 31% of its face value. Twenty years is long enough for two-thirds of the headline to evaporate.

People react to that in one of two ways. The unhelpful reaction is to conclude that investing is pointless. The useful one is to notice that inflation is precisely why a 6% fixed deposit is not "safe" — it is a slow, guaranteed way to stand still.

The real return rate, and why it is not a subtraction

Most people compute real return as "12% minus 6% equals 6%". That is an approximation that gets worse as the numbers get bigger. The correct relation divides growth factors:

real rate = ((1 + nominal) ÷ (1 + inflation)) − 1

At 12% and 6% that gives 5.66%, not 6%. The gap looks small until you compound it for thirty years, at which point the shortcut overstates the outcome by a wide margin.

This matters most at high inflation. At 12% returns and 10% inflation, subtraction says 2% while the real figure is 1.82% — a fifth less. The inflation and real returns guide works through more cases.

The other direction: pricing a goal

Inflation cuts both ways. If your target is "₹1 crore for a child's education in 18 years", the ₹1 crore is priced in today's money. Education inflation in India is widely reported as running ahead of general CPI, and even at a plain 6% you would need roughly ₹2.85 Cr by then to buy the same thing.

Planning to the un-inflated number is the single most common goal-planning error, and it is usually a 60–70% shortfall. The goal planner applies the inflation adjustment for you and then solves for the monthly SIP.

Before you rely on this

An estimate, not a forecast

This is arithmetic applied to assumptions you chose. Mutual funds carry market risk, returns are not guaranteed, and past performance does not indicate future results. Nothing here is personalised advice — for decisions of any size, speak to a SEBI-registered investment adviser.

Questions people actually ask

What inflation rate should I use?

India's CPI inflation has averaged close to 6% over the past decade, and the RBI's mandate targets 4% with a two-percentage-point band on either side. 6% is a reasonable default and 5–7% a reasonable range to test.

Your personal inflation is often higher than the index, because the index is a basket of national average spending. If your costs are dominated by school fees, healthcare or urban rent, model 8% and see whether the plan still works.

Does an inflation-adjusted SIP mean I should invest more each year?

That is exactly the sensible response, and it has a name: a step-up SIP. If your instalment stays flat for twenty years while prices rise 6% a year, you are quietly investing less in real terms every single year.

Raising the instalment roughly in line with inflation keeps your real commitment constant. Raising it in line with your salary does better than that. The step-up calculator quantifies both.

Is the real return the number I should compare against an FD?

Yes, and it is the comparison that changes minds. A fixed deposit at 7% against 6% inflation is a real return under 1%. After tax at a 30% slab, the post-tax rate is around 4.9%, which is negative in real terms.

That is not an argument that deposits are useless — they are the right tool for money you need within a couple of years. It is an argument against using them for twenty-year goals.

Why does the real value column sometimes fall below what I invested?

Because at a low enough return, or a high enough inflation rate, compounding never outruns rising prices. If your return assumption is below your inflation assumption, the real value of the corpus ends up worth less than the money you put in.

Seeing that happen on screen is the most useful thing this calculator does. It is the case for taking some risk, stated arithmetically.