CalcThai
calcthai.com · Inflation and Purchasing Power Calculator
Money & tax
Inflation and Purchasing Power Calculator
See how much today's price may rise in future, or what a future sum is worth today, at an average inflation rate, plus the real return after inflation.
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See how much today's price may rise in future, or what a future sum is worth today, at an average inflation rate, plus the real return after inflation.
How it works
Inflation factor = (1 + inflation)^years. Future price = today's price × factor. Today's value of a future sum = future sum ÷ factor. Purchasing power lost = 1 − 1 ÷ factor. Real return = (1 + return) ÷ (1 + inflation) − 1.
Hand check: 10% inflation for two years gives a factor of 1.21, so THB 100 becomes THB 121, and THB 121 in two years is worth THB 100 today, a 17.36% loss of purchasing power. A 1.5% return with 2% inflation is a real return of about −0.49% a year.
Uses a constant average inflation rate. Prices of different goods move differently, and school fees or healthcare may rise faster than general inflation. Taxes on returns are excluded.
Frequently asked questions
What inflation rate should I use?
The Bank of Thailand targets headline inflation within a range. Use the middle of that range or a reliable historical average, and a higher value for costs that rise quickly.
What does a negative real return mean?
Your money grows more slowly than prices. The balance rises, but it buys less.
Why not just subtract inflation?
Subtraction is an approximation that works for low rates. The division formula is more accurate, especially when rates are high.
Sources
Method last verified 21 Sep 2026