How to Calculate Investment Returns

Calculating investment returns correctly is essential for comparing different investment options, evaluating performance, and making informed financial decisions. Many investors confuse total return with annualised return, which leads to poor comparisons between investments held for different periods. This guide breaks down the three main return metrics — ROI, CAGR, and annualised return — with clear examples.

Return on Investment (ROI) – the simplest measure

ROI measures the total percentage gain or loss from an investment, regardless of how long you held it.

ROI = [(Final Value – Initial Investment) / Initial Investment] × 100

Example: You invested ₹1,00,000 in stocks. After 3 years, the portfolio is worth ₹1,60,000.

ROI = [(1,60,000 – 1,00,000) / 1,00,000] × 100 = 60%

ROI is useful for a quick comparison but problematic when comparing investments held for different durations. A 60% ROI over 3 years is very different from a 60% ROI over 10 years.

CAGR – the most important metric for comparing investments

CAGR (Compound Annual Growth Rate) converts any ROI into an annualised rate that accounts for compounding. It is the standard metric for comparing mutual funds, stocks, and other market investments.

CAGR = [(Final Value / Initial Value)^(1/Years)] – 1

Expressed as a percentage: multiply the result by 100.

Example: ₹1,00,000 grows to ₹1,60,000 over 3 years.

CAGR = [(1,60,000 / 1,00,000)^(1/3)] – 1 = (1.6)^0.333 – 1 = 1.1696 – 1 = 0.1696 = 16.96% per year

This is far more useful than the raw 60% ROI when comparing against a fixed deposit yielding 7% annually.

Why CAGR can be misleading

CAGR shows a smooth annual rate, which hides volatility. An investment that doubled then halved has a CAGR of 0%, but the investor experienced significant stress along the way. CAGR is best used alongside a maximum drawdown measure to understand both return and risk.

Absolute return vs CAGR – when to use each

• Use absolute return (ROI) for investments held under 1 year, or when you simply want to know the total profit/loss
• Use CAGR for investments held over 1 year, or when comparing multiple investments across different time periods
• Use XIRR for SIP investments or any investment with multiple irregular cash flows — XIRR is the internal rate of return that accounts for the timing of each transaction

Real return – accounting for inflation

Nominal return ignores the eroding effect of inflation. Real return shows your actual purchasing power gain.

Real Return ≈ Nominal Return – Inflation Rate

More precisely: Real Return = [(1 + Nominal Return) / (1 + Inflation Rate)] – 1

If your investment returns 12% annually and inflation is 6%: Real Return = [(1.12/1.06)] – 1 = 5.66% per year. Your actual purchasing power grew by only 5.66%, not 12%.

Comparing fixed deposit vs mutual fund returns

Fixed Deposit: ₹1,00,000 at 7% for 5 years (annually compounding)

Final value = 1,00,000 × (1.07)^5 = ₹1,40,255. CAGR = 7%.

Equity Mutual Fund: ₹1,00,000 grows to ₹2,20,000 over 5 years

CAGR = [(2,20,000/1,00,000)^(1/5)] – 1 = (2.2)^0.2 – 1 = 1.1707 – 1 = 17.07% per year

The mutual fund returned 17.07% CAGR vs FD's 7% CAGR — but the mutual fund carried equity risk, while the FD was guaranteed. Risk-adjusted comparison is essential.

Tax impact on investment returns

The real net return after tax is often lower than the reported return. Key considerations:

• Equity LTCG (Long Term Capital Gains): Gains above ₹1 lakh after 1 year taxed at 10% in India
• Equity STCG (Short Term Capital Gains): Gains within 1 year taxed at 15%
• Fixed Deposit interest: Taxed as income at your applicable slab rate (up to 30%)
• Debt Mutual Funds: Taxed as income at your slab rate

Post-tax CAGR is the most honest comparison metric for different investment types.

Frequently asked questions about investment returns

What is ROI and how do you calculate it? ROI = [(Final Value – Initial Investment) / Initial Investment] × 100. It measures total percentage gain regardless of time period.

What is CAGR? CAGR shows the annual rate at which an investment grew, assuming compounding. It is the most useful metric for comparing multi-year investments.

What is a good return on investment? This depends on the asset class. Indian equities have historically returned 12–15% CAGR over long periods. Fixed deposits offer 6–7%. Benchmark against inflation (5–6%) to assess real returns.

Practical checklist for evaluating investments

• Always use CAGR — not absolute return — when comparing investments held for different periods
• Factor in inflation to assess real purchasing power gains
• Calculate post-tax returns for a genuine comparison between asset classes
• Consider maximum drawdown and volatility alongside return metrics
• Use XIRR for SIP or any investment with multiple cash flows

Final takeaway

ROI tells you how much you made. CAGR tells you how fast you made it. Real return tells you how much richer you actually became after inflation. Using all three together gives you a complete picture of any investment's performance. Use the investment calculator below to model different scenarios with different rates and time horizons.