Understanding Inflation Adjustments
When your financial calculator tells you that you'll need a $500,000 bridge portfolio to retire early, is that $500,000 in today's money or in year-20 money? The answer determines whether your plan is realistic. This guide explains inflation adjustments and why they matter.
The Problem: Inflation Eats Your Purchasing Power
Money loses value over time. If inflation averages 2.5% per year, $100 today will buy only $77.59 worth of goods in 10 years. That's not because the goods became cheaper—it's because your dollar is worth less.
When you plan your retirement, you need to account for this. If you think you need $60,000 per year to live comfortably today, you'll actually need roughly $77,000 per year in 10 years (assuming 2.5% inflation)—just to afford the same lifestyle.
The question your calculator has to answer: "How much do you need to save?" Should it answer in today's dollars or in inflated future dollars? The answer is: today's dollars—because that's the only way you can make an apples-to-apples comparison with your current life.
Two Ways to Express Financial Goals
Nominal Dollars (Future Money)
Nominal dollars are the amount you'll literally have or spend at some future date—without any adjustment for inflation. They're the raw number you see on your bank statement in 10 years.
Example: "You'll need $77,000 per year in year 10 to have the same lifestyle you have today on $60,000."
Nominal dollars are hard to reason about because they hide the fact that you're planning for the same lifestyle. It feels like you need 28% more money, when really you're just accounting for the fact that money will be worth less.
Real Dollars (Today's Purchasing Power)
Real dollars are adjusted for inflation—they show what a future amount would be worth in today's purchasing power. Real dollars let you compare future spending to current spending apples-to-apples.
Example: "You'll need a purchasing power of $60,000 per year in year 10 to have the same lifestyle you have today on $60,000."
Real dollars are clearer because the number doesn't change—your lifestyle doesn't change, so the number shouldn't either.
A Concrete Example
Let's say you're 30 years old and want to retire at 50. Your assumptions:
- Current annual spending: $60,000
- Investment return: 7% per year
- Inflation: 2.5% per year
- Current savings: $100,000
If the calculator shows real dollars:
"Your bridge portfolio needs to reach $600,000 (in today's money) by age 50."
✅ This is clear: you need $600,000 in today's purchasing power. In year 20, that $600,000 will have the same buying power as $600,000 does today—enough to fund your $60,000/year lifestyle for the long term (based on these assumptions).
If the calculator showed nominal dollars:
"Your bridge portfolio needs to reach $819,000 (in year-20 money) by age 50."
❌ This is confusing: is $819,000 enough? How do I compare that to my current life? It's not clear until you remember that $819,000 in year 20 has the same purchasing power as $600,000 today. Why make your head do that extra work?
How the Calculator Builds Inflation In
The calculator works like this:
- Your input: "I spend $60,000 per year today."
- Calculation: Every year, your required spending grows by inflation (2.5%), so in year 20 you need $97,400 in nominal dollars.
- But simultaneously: Your investment returns also account for inflation. A 7% nominal return with 2.5% inflation is roughly a 4.4% real return (the return you actually get after inflation eats into it).
- Output: "You need $600,000 in today's purchasing power." That $600,000, invested at your real return rate, will fund your inflation-adjusted spending in retirement.
Both your spending and your returns are adjusted for inflation—they cancel out in the comparison, leaving you with a number that's easy to understand: today's dollars.
Why This Matters for Your Plan
1. It Makes Comparison Easy
You don't need to convert between inflation scenarios. Your target is in today's dollars, so you can compare it directly to your current savings, your current income, and your current lifestyle. No mental gymnastics.
2. It Reveals When You Can Actually Retire
Retirement happens when your portfolio reaches the target in today's money—not when it reaches some inflated nominal number in the future. The calculator tells you the real moment of freedom, not a confusing nominal figure.
3. It Accounts for Inflation Automatically
You don't have to adjust your spending target every year as inflation changes. Once you know you need $60,000/year (in today's purchasing power), that's it—inflation is already baked into the calculation.
4. It's Consistent with How You Think About Money
When you ask yourself "Can I live on $60,000 per year?", you're asking in today's dollars—the dollars you spend today. The calculator answers in the same units, making the plan feel real and achievable.
What Inflation Rate Should You Use?
The default in MyNextDollar is 2.5% per year, which is:
- Close to the RBA's long-term inflation target (2–3%)
- Aligned with historical Australian inflation over the past 20 years
- A reasonable baseline for conservative planning
If you believe inflation will be higher or lower, adjust it in the calculator. Even a 0.5% change compounds significantly over 20+ years:
| Inflation Rate | Purchasing Power of $100 in 20 Years |
|---|---|
| 1.5% | $74.00 |
| 2.0% | $67.30 |
| 2.5% | $61.04 |
| 3.0% | $55.37 |
| 3.5% | $50.21 |
If you expect higher inflation, you'll need a larger portfolio in today's dollars to maintain your purchasing power. The calculator handles this automatically when you adjust the inflation rate.
Common Misconceptions
"If inflation goes up, don't my returns also go up?"
Not automatically. Nominal returns (what you see in headlines) may stay the same while inflation increases, meaning your real return falls. That's why the calculator adjusts both sides—spending and returns—for inflation. You input the return you expect (historically, stock returns have slightly exceeded inflation), and the calculator shows what that's worth in real terms.
"Why do I even need to think about inflation if it's all in today's dollars?"
Because the inflation rate you choose affects your target. Higher inflation = higher target (in today's dollars) because your money will be worth less and you'll need more of it. The calculator accounts for this, but you should understand why your target number is what it is.
"Doesn't this mean my money will lose value in retirement?"
No. If your portfolio reaches $600,000 (in today's money) and you withdraw $60,000/year, you're maintaining your purchasing power. Your nominal balance will grow over time (due to returns exceeding your withdrawals), and the amount you withdraw will increase in nominal terms—but your actual lifestyle stays the same.
Key Takeaway
When MyNextDollar says "You need a bridge portfolio of $600,000," it means in today's purchasing power. That's the number that matters to your plan. In 20 years, the nominal value of your portfolio may be much higher (due to growth), but the purchasing power—what your money can actually buy—is what keeps you retired.
Thinking in real dollars, not nominal dollars, is how you turn a rough calculation into a plan you can actually follow.