Return on investment, and why the period matters
How a simple return differs from an annualised one, what belongs in the cost of an investment, and why ROI is easy to state and hard to state honestly.
Last reviewed · 1,315 words
In short
- A 60% return is 60% a year over one year, 17.0% over three and 9.9% over five. The same gain, three very different investments.
- Always report ROI with its period. A percentage without a timeframe is not a return, it is a number.
- Include every cost in the investment figure — fees, freight, time, and the money you could have earned elsewhere.
- ROI ignores risk entirely. A 30% return that could have been a total loss is not better than a certain 12%.
- For irregular cash flows, ROI is the wrong tool. Use XIRR or net present value.
Return on investment is the gain divided by what was invested:
ROI = (returned − invested) ÷ invested × 100
₹5,00,000 that becomes ₹8,00,000 has returned 3,00,000 ÷ 5,00,000 = 60%.
That is the whole formula, and almost every problem with ROI is about what goes into it rather than the arithmetic itself.
The period is not optional
A 60% return over one year and a 60% return over five years are not comparable, and quoting either as "60% ROI" without the period conceals the difference entirely.
annualised ROI = (returned ÷ invested)^(1 ÷ years) − 1
| Period | Simple ROI | Annualised |
|---|---|---|
| 1 year | 60% | 60.0% |
| 3 years | 60% | 17.0% |
| 5 years | 60% | 9.9% |
Over five years, 60% is 9.9% a year — respectable, and roughly what a decent debt fund does. Over one year it is exceptional.
Always annualise before comparing. A brochure quoting an absolute return over an unstated period is usually quoting a long one, and the annualised figure would be less impressive. Asking for it is the single most useful question to put to any investment claim.
What counts as the investment
The denominator is where honest and dishonest ROI calculations diverge, and the omissions are usually not deliberate.
Every acquisition cost. Brokerage, stamp duty, registration, freight, installation, customs duty. A machine invoiced at ₹10,00,000 that costs ₹1,20,000 to import and install is a ₹11,20,000 investment.
Ongoing costs, deducted from the return. Maintenance, storage, insurance, annual fees. Property returns quoted in India routinely omit maintenance, society charges and property tax, all of which are real.
Your own time, where it is substantial. A side business returning ₹2,00,000 on ₹5,00,000 looks like 40% until 400 hours of your own work is priced in.
Tax. A pre-tax return is not what you keep. Equity gains, debt gains, rental income and business profit are taxed differently, and comparing them before tax ranks them incorrectly.
Opportunity cost. Money in this investment is not in another. A 6% return when a risk-free deposit pays 7% is a loss in the only sense that matters.
Getting the denominator right usually reduces the return by more than any refinement of the numerator would improve it.
ROI ignores risk completely
This is the largest limitation and it is structural rather than fixable.
Two investments both return 20% over a year. One was a government bond; the other was a single small-cap stock that could plausibly have gone to zero. ROI reports them identically.
The measures that fill the gap are standard deviation, maximum drawdown, and simply asking what the worst realistic outcome was. An investment judged only on its realised return is judged on how the dice happened to land.
The practical form of this question: would you take this bet a hundred times? A 30% return earned by concentrating everything in one position looks excellent once and is ruinous as a policy.
Where the tool runs out
Irregular cash flows. ROI assumes one amount in and one out. Money added over time — a SIP, a business funded in tranches, a property with staged payments — needs XIRR, which accounts for when each rupee went in.
Ongoing income. A rental property produces monthly rent and a capital gain at the end. Total return needs both; ROI on the sale price alone misses most of it.
Comparing different lifespans. A three-year project and a ten-year one cannot be ranked by simple ROI. Annualise, or compare net present value.
Projects with no defined end. Marketing spend and equipment purchases produce returns over unclear horizons, and the ROI figure ends up being about the arbitrary window chosen.
Marketing ROI, and why it is usually overstated
ROI = (gross profit from campaign − campaign cost) ÷ campaign cost
Two errors are near-universal here.
Using revenue instead of gross profit. A campaign costing ₹1,00,000 that generates ₹5,00,000 of revenue at a 30% margin produced ₹1,50,000 of gross profit, so the return is 50%, not 400%.
Attributing sales that would have happened anyway. The correct measure is incremental — sales that occurred because of the campaign. Someone who was going to buy and clicked an advertisement first is not incremental revenue, and most attribution models count them.
A holdout group, where a comparable segment is deliberately not shown the campaign, is the only reliable way to measure the increment. It is rarely done, and campaign ROI figures should be read with that in mind.
Comparing across asset classes
ROI makes very different investments comparable only if the inputs are put on the same footing.
| Asset | Commonly omitted from the return |
|---|---|
| Property | Stamp duty, registration, brokerage, maintenance, property tax, vacancy |
| Gold | Making charges, storage, purity loss on resale |
| Equity funds | Tax on gains; the expense ratio is already deducted |
| Business | The owner's own time and salary |
| Fixed deposits | Tax at slab rate, which is the largest deduction of all |
Put each on the same basis — net of all costs, net of tax, annualised over the same period — before ranking them. Most comparisons that produce a surprising winner have simply left more costs out of one side.
A sanity check worth running
Convert any claimed return into an annualised rate and then ask what it implies.
A scheme offering to double money in three years is claiming 26% a year, sustained. Tripling in four years is 31.6%. Both are above what any large Indian fund has delivered over a long period, and any offer at that level is either taking enormous risk, which should be stated, or is not what it appears to be.
The arithmetic does not tell you which. It does tell you that a question is owed.
ROI on things that are not investments
The formula gets applied well beyond financial assets, and each use has a characteristic trap.
Education. The investment is fees plus the income forgone while studying, which is often the larger of the two. A two-year programme costing ₹20 lakh while giving up ₹12 lakh of salary is a ₹32 lakh investment, and the return is the increase in earnings, not the new salary.
Equipment. Include installation, training and downtime during changeover. The return is the labour or material saved, net of maintenance and power, over the machine's realistic life rather than its warranty period.
Software. The licence is usually the smallest component. Implementation, migration, training and the productivity dip during transition dominate the first year, and a twelve-month ROI on a system with a three-year payback will look like a failure.
Hiring. The investment is salary plus recruitment cost plus the ramp-up period. The return is what the person produces once productive, which for a senior role can be six months away.
In every case the pattern is the same: the visible cost is the smaller part, and the returns arrive later than the window people measure over.
Payback period, the simpler cousin
payback = investment ÷ annual return
An investment of ₹10,00,000 returning ₹2,50,000 a year pays back in four years.
It ignores the time value of money and everything that happens after payback, which makes it a poor ranking tool and a useful risk check. A two-year payback is recoverable if the assumption turns out wrong; an eight-year payback in a fast moving market is a bet on conditions eight years out.
Used alongside annualised ROI, it answers the question ROI does not: how long is the money exposed before it is back.
What this calculator assumes
- One amount invested and one amount returned, with no intermediate cash flows.
- The invested figure is whatever you enter — include fees, freight, duty and any other acquisition cost yourself.
- Annualisation uses compound growth, so it is directly comparable with CAGR and with any fund's published return.
- Figures are before tax unless you enter post-tax amounts on both sides.
- A negative return is reported as such rather than suppressed, and an investment of zero is an error rather than an infinite return.