Summary

The Excel TBILLYIELD function returns the yield for a Treasury bill from its settlement date, maturity date, and price. Microsoft defines it as the yield calculation counterpart to the bill-pricing functions, which makes it useful when price is known and yield is the missing output.

This function matters because Treasury bills are usually quoted and redeemed on a per-$100 face value basis. Once the purchase price is known, TBILLYIELD converts that price into the annualized bill yield implied by the bill's holding period.

TBILLYIELD is therefore best used as a reverse-yield function. It takes observed or modeled pricing information and converts it into a bill-yield measure.

Syntax

=TBILLYIELD(settlement, maturity, pr)

settlement is the date the bill is purchased, maturity is the maturity date, and pr is the bill price per $100 face value. Microsoft recommends using DATE for the date arguments to avoid ambiguity.

As with the other Treasury-bill functions, the bill must mature within one year of settlement. Invalid dates or an invalid price produce errors.

Arguments

• settlement - The bill's settlement date.
• maturity - The bill's maturity date.
• pr - The bill price per $100 face value.

The price input is per $100 face value, so the output yield should be interpreted within that same Treasury-bill convention.

TBILLYIELD vs Other Functions

TBILLYIELD belongs to the same Treasury-bill family as TBILLPRICE and TBILLEQ, but it solves a different unknown.

Use TBILLYIELD when the question is "what yield does this bill price imply?" rather than "what is the bill price?" or "what is the bond-equivalent yield?"

Using the TBILLYIELD Function

TBILLYIELD is useful in bill monitoring, secondary-market analysis, and sensitivity work. If the bill price moves, the implied yield moves in the opposite direction, so the function is a direct way to translate price changes into yield changes.

It is also helpful in screening models where the user sees bill prices but wants to compare the implied return against a hurdle rate or an alternative short-term instrument.

• Use DATE for settlement and maturity inputs.
• Remember that pr is a price per $100 face value.
• Use TBILLEQ instead if the bill has to be compared on a bond-equivalent basis.

Example 1 - Standard Yield Audit

This formula returns the annual bill yield implied by buying the T-bill at 99.2 and holding it until maturity. Because the bill redeems at $100, the yield comes from the gap between purchase price and face value over the bill's term.

=TBILLYIELD(DATE(2024,3,1),DATE(2024,6,1),99.2)

Example 2 - Lower Price Yield

Reducing the price to 98.5 increases the bill's implied yield. This shows the inverse relationship between price and yield in the Treasury-bill context.

=TBILLYIELD(DATE(2024,3,1),DATE(2024,6,1),98.5)

Example 3 - Performance Hurdle Check

This logical test checks whether the bill yield implied by a 99.2 price clears a 3% threshold. It is a practical pattern when the worksheet needs a quick screening rule.

=TBILLYIELD(DATE(2024,3,1),DATE(2024,6,1),99.2)>0.03

Example 4 - Yield Spread Calculation

Subtracting a 3% benchmark from the bill yield isolates the excess yield implied by the current purchase price. That spread is useful when ranking Treasury bills against a target or baseline rate.

=TBILLYIELD(DATE(2024,3,1),DATE(2024,6,1),99.2)-0.03

Conclusion Recap

• Summary: TBILLYIELD returns the annual yield implied by a Treasury bill's price.
• Syntax: =TBILLYIELD(settlement,maturity,pr).
• Core setup: Use valid dates, a valid bill price, and remember the price is per $100 face value.
• Best use: Yield recovery from price, Treasury-bill screening, and price-to-yield sensitivity analysis.