SIP vs lumpsum calculator

Take ₹5,000 a month for 20 years — ₹12 L in total. Fed monthly it becomes ₹49,95,740. Invested all at once on day one at the same 12%, that same ₹12 L becomes ₹1,15,75,552. This calculator shows why, and where the gap opens up.

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

The money, and the terms

₹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

Monthly against all-at-once

Total money, either way ₹12,00,000
Fed monthly (SIP) ₹49,95,740
All at once on day one ₹1,15,75,552
Lump-sum advantage ₹65,79,812
₹0₹37.5 L₹75 L₹1.13 Cr₹1.5 Cr036912151820

SIP valueLump-sum value

The lump sum is set to the SIP’s total outlay, so both columns spend the same money.
The same total money — ₹12,00,000 — spread monthly against invested all at once on day one.
YearSIP invested so farSIP valueLump-sum valueLump-sum lead
1₹60,000₹64,047₹13,44,000₹12,79,953
2₹1,20,000₹1,36,216₹15,05,280₹13,69,064
3₹1,80,000₹2,17,538₹16,85,914₹14,68,375
4₹2,40,000₹3,09,174₹18,88,223₹15,79,049
5₹3,00,000₹4,12,432₹21,14,810₹17,02,378
6₹3,60,000₹5,28,785₹23,68,587₹18,39,802
7₹4,20,000₹6,59,895₹26,52,818₹19,92,923
8₹4,80,000₹8,07,633₹29,71,156₹21,63,523
9₹5,40,000₹9,74,108₹33,27,695₹23,53,587
10₹6,00,000₹11,61,695₹37,27,018₹25,65,322
11₹6,60,000₹13,73,074₹41,74,260₹28,01,186
12₹7,20,000₹16,11,261₹46,75,171₹30,63,910
13₹7,80,000₹18,79,656₹52,36,192₹33,56,536
14₹8,40,000₹21,82,090₹58,64,535₹36,82,445
15₹9,00,000₹25,22,880₹65,68,279₹40,45,399
16₹9,60,000₹29,06,891₹73,56,472₹44,49,581
17₹10,20,000₹33,39,604₹82,39,249₹48,99,645
18₹10,80,000₹38,27,196₹92,27,959₹54,00,763
19₹11,40,000₹43,76,627₹1,03,35,314₹59,58,687
20₹12,00,000₹49,95,740₹1,15,75,552₹65,79,812

Why the lump sum wins on paper

It is not a mystery and it is not about market timing. It is exposure time.

In a 20-year SIP, your final instalment is invested for one month. Your 120th is invested for ten years. Only the first one gets the full twenty. On average, SIP money is invested for a little over half the period, so it earns a little over half the compounding.

The lump sum has every rupee exposed for the full term. Given the same positive return, it must end up ahead. The gap is arithmetic, not opinion.

Why almost everyone should still run a SIP

The comparison above is a fair test of a question most people do not face. To invest ₹12 L as a lump sum today, you must already have ₹12 L today. If you did, you would not be budgeting ₹5,000 a month.

For most people the real alternatives are "invest ₹5,000 a month" or "invest nothing", and against that baseline the SIP wins by an infinite margin. Three further points:

  • The comparison assumes one steady rate. Real markets do not deliver 12% a year; they deliver −18%, +31%, +4%. A SIP buys more units in the bad years, which is genuinely valuable in a volatile market and completely invisible in a smooth-rate model.
  • Timing risk is concentrated. A lump sum invested a month before a crash takes years to recover. A SIP spreads that decision across 240 dates.
  • Behaviour beats optimisation. A SIP you never think about outperforms a perfectly-reasoned lump sum you panic out of.

The longer version of this argument is in SIP vs lump sum, explained.

The answer most people land on

Both, for different money

Use a SIP for income — the salary that arrives monthly. Use a lump sum for capital that has already arrived: a bonus, a maturity, a windfall. They are not competing strategies, they are tools for two different kinds of money, and the question "which is better" mostly dissolves once you notice that.

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

So is lumpsum actually better than SIP?

At a constant positive return, yes, mathematically — and the calculator above shows by how much. But that result depends on an assumption real markets do not satisfy, and on your having the whole amount available today.

In a volatile or falling market a SIP can beat a lump sum outright, because averaging buys more units cheaply. The steady-rate model cannot show that, which is a limitation worth remembering rather than an argument to ignore the comparison.

I have a bonus. Should I invest it at once or spread it over a year?

Investing it at once has the higher expected value. Spreading it over three to six months lowers the chance of a bad entry date at a modest expected cost.

Either is defensible. What is not defensible is leaving it in a savings account for a year while you decide, which guarantees a real loss to inflation.

Does rupee cost averaging actually work?

It does exactly one thing reliably: it removes the need to pick an entry date. When prices fall, a fixed rupee amount buys more units, so your average cost per unit ends up below the average price over the period. That is arithmetic.

What it does not do is guarantee a better outcome than investing early in a rising market. It is risk management, not a return enhancer, and it is oversold as the latter.

What does this calculator assume?

Both columns spend the same total money and run for the same period at the same rate. The SIP instalment is treated as arriving at the start of each month and compounds monthly; the lump sum compounds annually, which is the convention for a single investment.

Both use one constant rate, with no volatility, costs, exit loads or tax. Every assumption is listed on the methodology page.