Real vs Nominal Returns: Inflation Is Silently Killing Your Savings

4% deposit interest per year! 5% money market fund return! 6% SBN coupon!

All these numbers sound positive. Your money is growing, right?

Not necessarily.

If inflation that year is 5%, your 4% deposit is actually making your purchasing power decrease. You have more Rupiah, but can buy fewer goods. This is the difference between nominal return and real return — a fundamental concept rarely discussed by banks or investment platforms.

This article will explain this concept with Indonesian data, so you don’t get fooled by numbers that look attractive on the surface.

📊 Definition: Nominal vs Real

Nominal Return

Nominal return is the investment growth number you see in reports — without accounting for inflation.

Examples:

• “BCA deposit interest 4.0% per year” ← this is nominal
• “Index fund up 15% this year” ← this is nominal
• “Gold up 8% from January to December” ← this is nominal

Nominal return is the “raw” number that hasn’t been adjusted.

Real Return

Real return is the growth in purchasing power — what percentage more goods and services you can buy with your investment compared to last year.

Examples:

• 4% deposit with 3% inflation → Real return ≈ 1%
• IHSG up 15% with 3% inflation → Real return ≈ 12%
• Gold up 3% with 5% inflation → Real return ≈ -2% (negative!)

Real return is what actually matters for your wealth.

🧮 How to Calculate Real Return

Simple Formula

For quick estimates:

Real Return ≈ Nominal Return – Inflation

4% deposit – 3% inflation = Real return ≈ 1%

Accurate Formula

For more precise calculation (important for long-term):

Real Return = ((1 + Nominal Return) / (1 + Inflation)) – 1

Example: 8% nominal return, 3% inflation:

• Simple formula: 8% – 3% = 5%
• Accurate formula: (1.08 / 1.03) – 1 = 4.85%

The difference is small for one year, but significant when compounded over 20-30 years.

Practical Calculation Example

You invest Rp 100,000,000 in a deposit with 4% interest for one year. Inflation that year is 3%.

With 0.2% real return, your purchasing power is practically stagnant. One year of waiting for nearly zero growth.

📈 Indonesian Historical Data: Who Beats Inflation?

Let’s look at how various instruments performed against Indonesian inflation over the past 10 years.

Indonesian Inflation 2015-2025

Source: BPS and Bank Indonesia

The 2015-2025 period was relatively mild due to tight monetary policy and stable commodity prices. The long-term average (2000-2024) approaches 4-5% per year, including inflation spikes in 2005 (17.1%) and 2008 (11.1%).

Real Return Comparison Across Instruments

The following table uses conservative estimates based on historical data:

Key message: Deposits and savings almost always lose to or break even with inflation. Only instruments with higher risk (stocks) or longer tenors (SBN, property) consistently provide positive real returns.

Visualization: Rp 100 Million in 20 Years

How Rp 100 million grows in 20 years with different real return assumptions:

Negative returns aren’t theory — this is reality for millions of Indonesians who put money in deposits over the past decade.

🏦 Why Don’t Banks Talk About Real Returns?

Because it doesn’t benefit them.

Banks profit from the spread: they pay you 4% deposit interest, then lend that money at 10%+. The more money in deposits, the bigger the bank’s profit.

If a bank said: “Our deposits provide 0% real return — your money doesn’t grow,” who would deposit?

So they display: “4% deposit interest! Safe and LPS guaranteed!” — which isn’t factually wrong, but hides the complete picture.

Your job: Always calculate real return yourself. Don’t trust nominal numbers displayed in marketing.

🎯 Implications for Investment Targets

If you’re targeting retirement funds or long-term goals, inflation must enter the calculation.

Example: Retirement Fund Target

You want to have “Rp 5 billion at retirement 20 years from now” to live comfortably.

Problem: Rp 5 billion in 20 years is not the same as Rp 5 billion today.

With 3% annual inflation, Rp 5 billion’s purchasing power in 20 years equals:

Rp 5,000,000,000 / (1.03)^20 = Rp 2.77 billion today

Meaning, if your target is purchasing power equivalent to Rp 5 billion today, you need to target Rp 9 billion in 20 years (assuming 3% inflation).

Better Approach: Target in Real Returns

Instead of targeting nominal amounts, target real returns:

• “I want my portfolio to grow 6% above inflation per year”
• With 3% inflation, this means target nominal return = 9%
• With 5% inflation, this means target nominal return = 11%

Real return-based targets are more robust because they automatically adjust to inflation conditions.

⚠️ Your Felt Inflation May Be Higher

Official BPS inflation numbers are national averages for a specific basket of goods. Your inflation may differ depending on consumption patterns.

Inflation by Category

If you have children heading to college, education cost inflation is a more relevant benchmark than general inflation.

Personal Inflation Rate

You can calculate personal inflation:

1. Record regular monthly expenses this year
2. Compare with expenses for the same goods/services last year
3. Calculate the percentage increase

If your personal inflation is 6% while deposits yield 4%, your real return is -2% — worse than what official numbers show.

📌 Checklist: Evaluating Investments with Real Returns

Before choosing an investment instrument, ask:

1. What nominal return is offered?

   • Make sure this is after tax and fees

2. What inflation am I assuming?

   • Conservative: 4-5%
   • Optimistic: 2-3%

3. What’s the real return?

   • Nominal return – inflation
   • Must be positive for purchasing power growth

4. Is this real return sufficient for my goals?

   • Emergency fund: 0% real is fine (liquidity matters)
   • Long-term goals: need 3-5%+ real

5. Consistent or volatile?

   • Deposits: consistent real return (but low/negative)
   • Stocks: high long-term real return, but volatile annually

💡 Conclusion: Don’t Be Fooled by Nominal Numbers

Nominal returns are an illusion if you don’t account for inflation. Your money may “grow” in numbers, but shrink in purchasing power.

Key lessons:

1. Deposits aren’t investments — they’re money parking that (often) loses to inflation
2. Real returns matter — not numbers in bank reports
3. Long-term targets must account for inflation — Rp 1 billion in 20 years ≠ Rp 1 billion today
4. Higher real return instruments = higher risk — no shortcuts

For passive investors, index mutual funds and retail SBN are choices that historically provide positive real returns with managed risk. Deposits may be “safe” for nominal amounts, but don’t protect your real wealth.

Understand real returns. Calculate before investing. And don’t let inflation silently kill your savings.

Related Reading

• Inflation and Why Deposits Alone Aren’t Enough — Focus on deposits vs inflation
• Money Market Funds vs Deposits — Alternatives for parking money
• Retail SBN: Complete Guide — Government-guaranteed positive real return instruments
• Index Mutual Funds — Long-term strategy to beat inflation
• Retirement Savings — Planning with inflation as a factor