Treasury TIPS Real Yield Calculator
Calculate the composite return, real yield, nominal yield, and inflation-adjusted principal of Treasury Inflation-Protected Securities (TIPS) using the official composite rate formula.
What Are Treasury TIPS and How Do They Work?
Treasury Inflation-Protected Securities (TIPS) are US government bonds where the principal automatically adjusts based on changes in the Consumer Price Index (CPI). If CPI rises 3%, a $10,000 TIPS becomes $10,300 in principal. Your coupon (fixed rate) is paid on this adjusted principal, so both your interest payments and your final repayment are inflation-protected. TIPS are issued with 5-, 10-, and 30-year maturities and are available through TreasuryDirect.gov and on secondary markets. Source: SEC.gov Investor Bulletin on TIPS. Last updated: May 2026.
TIPS Composite Return Formula
The TIPS composite return is not a simple addition of fixed rate + CPI. The correct formula is: Composite = (1 + fixed rate) × (1 + CPI rate) − 1. At a 2% fixed rate and 3.2% CPI, the composite is (1.02 × 1.032) − 1 = 5.264%, not the simple-sum 5.2%. This cross-product term matters more at higher inflation rates. The calculator above uses the exact formula.
| Fixed Rate | CPI Rate | Simple Sum | Correct Composite | Difference |
|---|---|---|---|---|
| 2.0% | 3.0% | 5.00% | 5.06% | +0.06% |
| 2.0% | 5.0% | 7.00% | 7.10% | +0.10% |
| 2.0% | 8.0% | 10.00% | 10.16% | +0.16% |
TIPS vs Nominal Treasuries vs I-Bonds
Nominal Treasuries pay a fixed nominal yield — if inflation beats that yield, your real return is negative. TIPS guarantee a positive real return as long as CPI is measured correctly. I-Bonds also use the composite formula but have a $10,000/year purchase cap and are non-tradeable. TIPS are better for large institutional allocations, laddering strategies, and retirement accounts where phantom income tax on CPI adjustments is deferred. The breakeven inflation rate — where TIPS and nominal Treasuries produce the same nominal return — is a key market signal watched by the Federal Reserve.