What it costs to start a SIP a year late

Why a year of waiting costs more than twelve deposits

The intuitive answer is that waiting a year costs twelve monthly payments. If you plan to invest ₹10,000 a month, you assume you lose ₹1.2 lakh. That would be true if the money earned nothing. A plan that earns a return behaves differently, because every deposit grows on its own timetable.

Imagine the plan runs for 240 months with a fixed end date. The deposit in month 1 has 239 months to grow. The deposit in month 240 has none. If you delay the start by a year, you do not shift the whole schedule forward. You lose the first twelve slots, which are the slots with the longest time to compound, and the end date stays where it was.

Here is the same fact stated with numbers. The twelve deposits you skip add up to ₹1.2 lakh. If they had been made, they would be worth about ₹1.27 lakh at the end of the first year. That sum would then keep growing for the remaining 228 months at 1% a month, which multiplies it by about 9.7. The result is about ₹12.3 lakh. That is the cost of waiting: a small deposit with a very long runway.

Three ideas follow from this:

• The cost sits at the end of the plan. You will not feel it for years. The shortfall appears on the date you need the money.
• The first year costs the least of all the years you might wait. The second year of delay costs more than the first, and the third more than the second.
• The cost grows with the rate and with the time left. A short plan at a low return has a small gap. A long plan at a higher return has a large one.

The SIP delayed start calculator makes this comparison on one screen. You enter the monthly amount, the assumed return, the total time and the delay in months, and it shows the pot from starting now, the pot from starting later and the gap between them. The SIP delayed start guide explains each input if you want a step-by-step walkthrough, and the year you wait to invest tells the same story as a short read.

What each delay costs at the same end date

Every figure below assumes ₹10,000 a month, deposits at the end of each month, a 12% annual return compounded monthly, and a fixed 20-year end date. Only the start changes.

• Start today (240 deposits): about ₹98.9 lakh from ₹24 lakh invested.
• Wait 6 months (234 deposits): about ₹92.6 lakh. The wait costs about ₹6.3 lakh for ₹60,000 of skipped deposits.
• Wait 1 year (228 deposits): about ₹86.7 lakh. The wait costs about ₹12.3 lakh for ₹1.2 lakh skipped.
• Wait 2 years (216 deposits): about ₹75.8 lakh. The wait costs about ₹23.1 lakh for ₹2.4 lakh skipped.
• Wait 3 years (204 deposits): about ₹66.1 lakh. The wait costs about ₹32.8 lakh for ₹3.6 lakh skipped.
• Wait 5 years (180 deposits): about ₹50.0 lakh. The wait costs about ₹49.0 lakh for ₹6 lakh skipped.

Read the last line twice. A five-year wait removes 25% of the deposits and about half of the final pot. The person who waited still deposited ₹18 lakh, which is 75% of what the early starter paid in. The difference is almost entirely compound growth that the late starter never received.

The same pattern shows up at different monthly amounts because the arithmetic scales. At ₹5,000 a month the one-year delay costs about ₹6.1 lakh on a pot of about ₹49.5 lakh. At ₹25,000 a month the cost is about ₹30.7 lakh on a pot of about ₹2.47 crore. The share lost is the same, about 12.4% of the final value for a one-year delay in a 20-year plan at 12%.

How the assumed return changes the gap

An obvious objection is that 12% is a generous assumption. It may be. Market-linked returns vary from year to year and can be negative for several years in a row. The sensible response is to run the plan at several rates and look at the whole range. Here is the cost of a one-year delay for ₹10,000 a month over 20 years:

• At 0%: ₹1.2 lakh, exactly the deposits you skipped.
• At 4%: about ₹2.6 lakh, on a pot of about ₹36.7 lakh.
• At 6%: about ₹3.8 lakh, on a pot of about ₹46.2 lakh.
• At 8%: about ₹5.7 lakh, on a pot of about ₹58.9 lakh.
• At 10%: about ₹8.3 lakh, on a pot of about ₹75.9 lakh.
• At 12%: about ₹12.3 lakh, on a pot of about ₹98.9 lakh.

The cost shrinks as the rate falls, which you would expect. It never falls below the skipped deposits. Any positive return pushes the cost above ₹1.2 lakh, so the early start wins at every rate above zero. If the rate you typed is a hopeful number, drop it by two or three points and note what the gap looks like. A plan that only works at the highest rate is a hope rather than a plan.

For another view of the same effect, the article on a monthly investment over 10, 20 and 30 years shows the pot at several time spans, and the compound interest calculator lets you see how time and rate change the curve.

Why the last years carry so much of the result

Compounding is back-loaded. Most of the money in a long plan arrives near the end. Take the same ₹10,000 a month at 12%:

• After 5 years the pot is about ₹8.2 lakh, from ₹6 lakh deposited.
• After 10 years it is about ₹23.0 lakh, from ₹12 lakh deposited.
• After 15 years it is about ₹50.0 lakh, from ₹18 lakh deposited.
• After 20 years it is about ₹98.9 lakh, from ₹24 lakh deposited.

The last five years add about ₹48.9 lakh, nearly as much as the whole first fifteen years put together. That is why the order of deposits matters so much. The money you put in early sits inside the pot during the stretch when it is growing fastest in rupee terms, even though a rupee-for-rupee growth rate is the same every month.

Removing early deposits removes a piece of that late-stage growth. Removing late deposits changes the total only by the deposit amounts themselves. A year skipped at the start is therefore expensive. A year skipped at the end is not. If you must choose between investing now and investing later with the same end date, choose now.

Different horizons, same lesson

A one-year delay hurts more the longer the plan. With ₹10,000 a month at an assumed 12%:

• 10-year plan: the pot falls from about ₹23.0 lakh to about ₹19.3 lakh. The delay costs about ₹3.7 lakh.
• 15-year plan: the pot falls from about ₹50.0 lakh to about ₹43.2 lakh. The delay costs about ₹6.7 lakh.
• 20-year plan: from about ₹98.9 lakh to about ₹86.7 lakh. The delay costs about ₹12.3 lakh.
• 30-year plan: from about ₹3.49 crore to about ₹3.09 crore. The delay costs about ₹40.5 lakh.

A short plan feels safe to postpone because the cost looks modest. A long plan, such as saving for retirement, is the one where each year of delay is most costly, and the one where most people start late. The point is not that you must hit a particular amount, but that the price of waiting grows quickly with the length of the plan.

Six steps to compare starting now and starting later

1. Choose a monthly amount you can keep up in a bad month. If ₹10,000 feels tight, choose ₹5,000 and raise it later.
2. Fix the end date. Count the total months to the date you need the money. A plan to buy a house in 15 years is 180 months.
3. Open the SIP delayed start calculator and enter the amount, the months and a cautious return. Add the number of months you are thinking of waiting.
4. Read the gap. Note both the final pots and the difference between them. Write the gap next to the deposits skipped.
5. Repeat at two more returns. Use one lower and one higher figure so you see a range, not a point.
6. Run the on-time plan in the SIP calculator. Use the step-up option to see how rising the amount each year changes the result, and then decide on the amount and the start date.

How much more would it take to catch up?

Suppose you did wait and now want the same final amount on the same date. You have three levers: invest more each month, extend the end date, or add lump sums.

Invest more each month. After a one-year delay in the ₹10,000 plan, the 228 remaining months must produce ₹98.9 lakh. That needs about ₹11,415 a month, which is about 14% more. After a five-year delay, you have 180 months, and the required payment is about ₹19,800 a month, almost double the original.

Extend the date. At ₹10,000 a month, you need about 12 extra months to match a one-year delay, so a 21-year plan rather than a 20-year one. The delay in time is roughly equal to the delay in start.

Add lump sums. A single deposit made now has the full remaining time to grow. At 12% over 19 years, ₹1,00,000 grows to about ₹8.6 lakh, while over 20 years it grows to about ₹9.6 lakh. A lump sum of about ₹1.3 lakh made now grows to about ₹12.5 lakh over 20 years, which roughly matches the cost of a one-year delay.

The comparison shows why a one-year delay is easier to fix than a five-year one. The catch-up amount rises faster than the delay. Decide early which lever you will use, or the lever you choose may no longer be affordable.

A small start beats a late perfect start

Many people delay because they cannot yet invest the amount they want. Compare two choices over the same 20-year horizon at 12%.

• Wait 12 months, then invest ₹10,000 a month for 19 years. The pot is about ₹86.7 lakh.
• Invest ₹5,000 a month for the first 12 months, then ₹10,000 a month for 19 years. The first year adds about ₹6.1 lakh at the end, and the pot is about ₹92.8 lakh.

The second choice deposits only ₹60,000 more than the first and ends with about ₹6.1 lakh more. A modest start in year one earns more than waiting to start big.

A step-up plan is a natural extension. Raise the monthly amount by a fixed percentage each year, in line with your pay. Starting at ₹5,000 and raising it 10% a year for 20 years reaches about ₹98.5 lakh at 12%, almost the same as a flat ₹10,000 from day one, which gives about ₹98.9 lakh. Starting at ₹10,000 with a 10% yearly step-up reaches about ₹1.97 crore. The SIP calculator guide shows how to set the step-up in the tool.

Worked example: Ananya waits eighteen months

Ananya is 30. She wants to build a fund for a down payment in 15 years and plans to invest ₹15,000 a month. She is tempted to wait 18 months until a pay review.

Inputs

• Monthly investment: ₹15,000, deposits at the end of each month.
• Assumed return: 12% a year, 1% a month.
• End date: 180 months from now.
• Option A: start now with 180 deposits. Option B: start in 18 months with 162 deposits.

Calculation

Step 1: pot with an immediate start. The deposit multiplier for 180 months at 1% is about 499.6. ₹15,000 × 499.6 is about ₹74.9 lakh.

Step 2: pot with an 18-month delay. The multiplier for 162 months is about 401.3. ₹15,000 × 401.3 is about ₹60.2 lakh.

Step 3: the cost of waiting. ₹74.9 lakh minus ₹60.2 lakh is about ₹14.7 lakh. The skipped deposits were 18 × ₹15,000, which is ₹2.7 lakh.

Step 4: the catch-up payment. To reach ₹74.9 lakh in 162 months she would need about ₹18,675 a month, which is about 25% more than she planned.

Step 5: a compromise. If she invests ₹7,500 a month during the 18 months and then ₹15,000 for 162 months, the pot is about ₹67.6 lakh. Half-rate saving during the delay recovers about ₹7.4 lakh of the ₹14.7 lakh gap.

Result

Waiting 18 months for a pay review costs Ananya about ₹14.7 lakh at an assumed 12%. Even a small start of ₹5,000 a month in the meantime would bring the pot to about ₹65.1 lakh, recovering about ₹4.9 lakh. If the review is certain, a half-rate start now and a full-rate start after the raise is a far better path than a clean break.

What about a lump sum?

A lump sum follows the same logic with a simpler formula. At 12% a year, money grows by a factor of 1.12 each year. For ₹1,00,000, 20 years gives about ₹9.65 lakh and 19 years about ₹8.61 lakh. Waiting one year costs about ₹1.04 lakh, which is a year of growth on the final amount.

If you have a large lump sum and worry about investing it all at once, you can spread it over six or twelve months. The lump sum versus SIP calculator compares both paths, and the guide to SIP versus lump sum for beginners and the blog on SIP versus lump sum investing explain the trade-off. Spreading reduces the risk of a poor entry date. It also keeps part of the money out of the market for a while, which has a cost if markets rise.

When waiting is the right choice

None of this means every delay is a mistake. There are good reasons to hold off, provided you set a date.

• You carry high-interest debt. Paying off a card at 30% or more is a guaranteed saving that beats any investment assumption. Clear it first.
• You have no emergency fund. A SIP should not be the money you sell to cover a repair or a job gap. Build a buffer first, then start.
• You need the money within about three years. Market-linked investments can fall over short periods. Short goals fit a savings product better.
• Your income is unsteady. A plan you must stop after four months teaches the wrong habit. Start smaller and keep it steady.
• You do not yet understand the product. Read the scheme documents, the costs and the risks, then start with a modest amount.

In each case, treat the wait as a project with a finish line. The mutual fund SIP checklist lists what to confirm before you commit, and the article on how much emergency fund you need helps with the buffer. Then start.

Common mistakes to avoid

• Treating the assumed return as a promise. It is an input. Test lower rates and plan around the cautious one.
• Counting only the skipped deposits. The larger cost is the growth those deposits would have earned.
• Waiting for a perfect amount. A small plan started now often beats a large plan started later.
• Waiting for a market fall. The calendar moves every month, and nobody can pick the low in advance.
• Moving the end date with the start date. Compare plans on the same end date or you will hide the cost.
• Stopping after a bad year. Stopping turns a paper loss into a real one and skips deposits at lower prices.
• Ignoring costs and tax. Fees and tax reduce the return you keep. Fold them into the rate you assume.
• Setting and forgetting. Review the amount once a year and raise it as your pay rises.

Checklist before you start a SIP

• Write down the goal and the date you need the money.
• Convert the time to months so the calculator inputs are exact.
• List card or loan debt above about 15% a year and decide whether to clear it first.
• Confirm that at least one to three months of costs sit in a safe account.
• Run the delayed start calculator at a cautious, a middle and a higher return.
• Note the cost of waiting for six months, one year and two years.
• Choose a monthly amount you can pay in your weakest month.
• Set up an automatic payment for the day after your pay arrives.
• Pick a step-up rule, such as 10% more each year or each pay rise.
• Keep money you may need within three years in a separate, safer place.
• Check the costs of the product you choose, including fund charges and exit loads.
• Invest bonuses as a separate lump sum instead of delaying the monthly plan.
• Set a yearly review date and rerun the SIP calculator then.

Frequently asked questions