TIPS Calculator (Treasury Inflation-Protected)

Calculate TIPS real return and inflation-adjusted principal. Compare to nominal Treasury bonds.

By Konstantin Iakovlev · Updated September 2026 · Source: TreasuryDirect — Treasury Inflation-Protected Securities (TIPS)

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%
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Years to Maturity

Total Value at Maturity

$15,749.01

Adjusted Principal

$13,439.16

Total Coupon Income

$2,309.84

TIPS Return Summary

Original Principal$10,000.00
Inflation-Adjusted Principal (10 yr)$13,439.16
Principal Appreciation$3,439.16
Total Coupon Payments$2,309.84
Total Return$5,749.01
Annualized Nominal Return4.65%
Annualized Real Return2.00%

TIPS vs Nominal Treasury

Nominal Treasury Yield (est.)5.00%
Nominal Treasury Total$15,000.00
Nominal Real Value (after inflation)$11,161.41
TIPS Total Value$15,749.01
If inflation is higher than expectedTIPS wins
If inflation is lower than expectedNominal wins

Growth Over Time

Year 5Principal: $11,592.74 | Coupons: $1,069.73
Year 10Principal: $13,439.16 | Coupons: $2,309.84

Planning income for retirement? Price a whole ladder of TIPS, one maturing each year, from current Treasury prices: TIPS ladder calculator

Use the TIPS Calculator (Treasury Inflation-Protected) above to calculate your results. Enter your values and see instant results — all calculations run in your browser.

Disclaimer: This calculator is for informational purposes only and does not constitute tax, financial, or legal advice. Results are estimates based on the information you provide and current rates. Always consult a qualified tax professional or financial advisor for advice specific to your situation.

How It Works

Treasury Inflation-Protected Securities exist to defend the purchasing power of your money, and this tool projects two things that ordinary bonds hide: your inflation-adjusted principal and your real return. The distinction matters because inflation quietly erodes the true value of any fixed-rate holding.

The math begins with the inflation-adjusted principal, found by multiplying your original principal by the cumulative inflation factor, which is simply 1 plus the CPI-U change. Subtracting that inflation adjustment from the nominal return leaves the real return, the number that actually tells you whether your buying power grew.

Two tax and structural quirks deserve attention. TIPS interest and principal adjustments are both taxed as federal income each year, even when you receive no cash for the principal bump. Deflation, while uncommon, can pull your principal below its original par value during the bond's life, but you will never be repaid less than par at maturity.

Example: $10,000 in a 5-Year TIPS

  1. 1 Input: $10,000 in a 5-year TIPS with a 2% real coupon, assuming 3% inflation every year (the calculator's default rates; actual CPI-U will differ).
  2. 2 Principal: it is indexed to inflation, so at maturity it has grown to $10,000 × 1.03^5 = $11,592.74.
  3. 3 Coupons: 1% of the adjusted principal every six months. In year 1 that is $100.00 on $10,000 plus $101.49 on $10,148.89 = $201.49; by year 5 the coupons come to $226.78 a year, and the five years total $1,069.73.
  4. 4 Result: $11,592.74 + $1,069.73 = $12,662.47, a $2,662.47 return, or 4.83% a year in nominal terms. The real return stays at the 2% coupon, because the principal growth only keeps pace with inflation. At maturity Treasury pays the adjusted principal or the original $10,000, whichever is greater.

Source: TreasuryDirect — Treasury Inflation-Protected Securities (TIPS) · Last updated: September 2026

Frequently Asked Questions

What are TIPS and how do they protect against inflation?
Treasury Inflation-Protected Securities (TIPS) are US government bonds whose principal adjusts with the Consumer Price Index. If inflation rises 3%, your principal increases 3%, and your fixed interest rate is applied to the higher amount, preserving your purchasing power.
When are TIPS a good investment?
TIPS come out ahead of a regular Treasury of the same maturity when inflation over the bond's life exceeds the break-even rate, which is the nominal Treasury yield minus the TIPS real yield. Compare the two yields on the day you buy: if you expect inflation above that gap, TIPS are the better hedge.
How are TIPS taxed?
TIPS interest and the annual inflation adjustment to principal are both taxed as ordinary income at the federal level, even though you do not receive the principal adjustment until maturity. This "phantom income" issue makes TIPS best held in tax-advantaged accounts like IRAs.

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