Summary

The Excel TBILLEQ function returns the bond-equivalent yield for a Treasury bill. Microsoft defines it as a yield conversion function for T-bills, which makes it useful when a bill quoted on a discount basis needs to be compared with securities quoted on a bond-yield basis.

That distinction matters because a Treasury bill discount rate is not the same as a bond-equivalent yield. The two measures use different conventions, so the bond-equivalent yield is usually somewhat higher than the quoted bill discount rate for the same instrument.

TBILLEQ is therefore best treated as a comparison function. It converts a bill quote into a more bond-like yield measure so that relative analysis across instruments becomes more meaningful.

Syntax

=TBILLEQ(settlement, maturity, discount)

settlement is the date the bill is purchased, maturity is the date it matures, and discount is the quoted bill discount rate. Microsoft recommends building the dates with DATE to avoid interpretation problems.

As with the other Treasury-bill functions, the bill must mature within one year of settlement. Invalid dates or discount values return errors.

Arguments

• settlement - The bill's settlement date.
• maturity - The bill's maturity date.
• discount - The quoted bill discount rate.

The result is a yield, not a price. It is meant for comparison with other annualized yield measures rather than for direct price calculations.

TBILLEQ vs Other Functions

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

Use TBILLEQ when the main goal is comparability across instruments, not just bill pricing or bill-yield recovery.

Using the TBILLEQ Function

TBILLEQ is most useful when a Treasury bill has to be compared with other fixed-income choices. A raw bill discount rate can be misleading if it is placed beside bond yields without conversion, so TBILLEQ helps put those figures onto a more comparable basis.

It is also helpful in relative-value analysis because the gap between the bill discount rate and the bond-equivalent yield shows how much convention alone can change the apparent annual rate.

• Use DATE for settlement and maturity inputs.
• Remember that the output is a yield conversion, not a price.
• Use TBILLEQ when the question is about comparability with bond-yield quotations.

Example 1 - Standard Bond Yield

This formula converts a 3% Treasury-bill discount quote into a bond-equivalent yield. The result is slightly above 3% because the bond-equivalent convention is not identical to the raw discount convention.

=TBILLEQ(DATE(2024,3,1),DATE(2024,6,1),0.03)

Example 2 - 90-Day Audit

Using a 3.5% discount rate on the same bill dates produces a higher bond-equivalent yield. This makes the formula useful for sensitivity analysis across different quoted discount levels.

=TBILLEQ(DATE(2024,3,1),DATE(2024,6,1),0.035)

Example 3 - Yield Hurdle Check

This logical test checks whether the bond-equivalent yield clears a 3% hurdle. It is a practical screening pattern when T-bills are being compared with other income options.

=TBILLEQ(DATE(2024,3,1),DATE(2024,6,1),0.03)>0.03

Example 4 - Yield Spread Calculation

Subtracting the discount rate from the bond-equivalent yield isolates the convention gap between the two measures. That gap helps explain why a T-bill can appear to offer different annual rates depending on the quoting basis used.

=TBILLEQ(DATE(2024,3,1),DATE(2024,6,1),0.03)-0.03

Conclusion Recap

• Summary: TBILLEQ returns the bond-equivalent yield for a Treasury bill.
• Syntax: =TBILLEQ(settlement,maturity,discount).
• Core setup: Use valid bill dates and remember the output is a bond-comparable yield, not the raw bill discount rate.
• Best use: Fixed-income comparison, yield normalization, and Treasury-bill relative-value analysis.