About the SIP vs Lump Sum Calculator
This SIP vs lump sum calculator answers a common question: if you have a sum of money ready to invest, should you put it all in today or feed it into the market through a systematic investment plan (SIP) over several months? Enter the amount, how many months you would spread it over, your expected annual return and your investment horizon, and it shows the final value of both approaches side by side.
It suits anyone holding a bonus, inheritance, property sale proceeds or maturing deposit — whether investing in mutual funds, index funds or ETFs. You can also enter the interest earned on the cash that is waiting to be invested, which makes the comparison fairer to the SIP approach.
The model assumes a steady return every month, so the lump sum always wins when the expected return is above the cash rate: more money is invested for longer. In real markets returns are uneven, and spreading purchases reduces the risk of investing everything just before a fall. The chart shows the cost of that insurance in a typical, smooth-growth scenario.
With the default inputs, the lump sum advantage is $6,595.93. Change any value above to recalculate instantly.
How to use the sip vs lump sum calculator
- 1Enter the total amount you have ready to invest.
- 2Choose how many months you would spread the SIP over.
- 3Enter a realistic expected annual return and your time horizon.
- 4Add the interest rate the waiting cash would earn, if any.
- 5Compare the final values and the chart to see what spreading your entry costs.
Formula and method
The lump sum is invested at month 0 and compounds for all T months of the horizon. The SIP splits the same amount A into n equal installments invested at the start of each month, so installment k compounds for T − k months. The annual return R is converted to an equivalent monthly rate i so that 10% a year really means 10% a year.
Money waiting to be invested earns the cash rate you enter, compounded monthly; the interest it earns is swept into the investment when the SIP period ends. The difference between the two final values is the cost (or benefit) of spreading your entry, assuming the return is earned smoothly every month.
- A
- Total amount available to invest
- n
- Number of monthly SIP installments
- T
- Investment horizon in months
- R
- Expected annual return
- i
- Equivalent monthly return
Worked examples
$60,000 over 12 months vs all at once
At 10% a year, $60,000 invested today grows to about $155,625 after 10 years. Investing $5,000 at the start of each month for a year instead leaves part of the money idle, so the SIP ends near $149,029 — about $6,596 behind in a smoothly rising market.
$100,000 over 24 months with cash earning 4%
Spreading $100,000 over two years at $4,166.67 a month, with the waiting cash earning 4%, gives about $305,732 after 15 years at 8%. The lump sum reaches about $317,217, so the gradual approach costs roughly $11,485 — the price of protection against a badly timed entry.
Short 6-month SIP into a 5-year horizon
Spreading $60,000 over just six months while the rest earns 4.5% keeps the gap small: $96,631 for the lump sum versus $95,597 for the SIP after five years at 10%, a difference of about $1,033.
Frequently asked questions
Is SIP better than lump sum?+
When markets rise over time, a lump sum usually ends with more money because it is invested for longer. A SIP wins when prices fall during the months you are spreading your purchases. Research on historical markets generally finds lump-sum investing ahead in roughly two-thirds of periods, but a SIP reduces regret and timing risk.
What is the difference between SIP and STP?+
A SIP invests fresh money each month from your income or bank account. A systematic transfer plan (STP) parks a lump sum in a liquid or debt fund and transfers a fixed amount into an equity fund each month. Use the cash-interest input here to model an STP.
Why does the lump sum win in this calculator?+
The calculator assumes the same return every month, so money invested earlier always compounds for longer. To see a SIP win you would need a period of falling prices, which a steady-return projection cannot capture. Enter a cash rate above the expected return to see that case.
How long should I spread a lump sum?+
Many investors spread a large sum over 6 to 12 months, which limits how long the money sits idle while reducing the risk of investing everything at a peak. Spreading beyond 12 to 24 months usually leaves too much cash out of the market.
Does this work for mutual funds in India?+
Yes. The maths is the same in any currency: type your amount in rupees and use an expected return that fits the fund category. Taxes, exit loads and expense ratios are not included in the projection.
Results are estimates for educational purposes and are not financial advice. Rates, fees and terms vary — confirm with your lender or a licensed advisor before making decisions.