Zoho Sheet TBILLYIELD: Calculate yield from a Treasury bill price

=TBILLYIELD(settlement; maturity; issue_price)

Zoho defines issue_price as the price per $100 par value. Settlement and maturity are dates, and all three arguments are required. There is no basis or coupon-rate argument. Official TBILLYIELD reference.

Use 98 to mean a quoted price of 98 per 100 par. Entering 0.98 would describe a dramatically different price, not the same quotation expressed as a percentage. The result is a rate, so percentage formatting is useful for the output.

In a fresh worksheet enter:

In B6 enter =TBILLYIELD(B2;B3;B4). The independent reference is 0.0816326530612245. Equivalently:

=TBILLYIELD(DATE(2025;1;1);DATE(2025;4;1);98)

The 90-day holding-period gain is 2 per 100 par, relative to price 98. Independently calculate:

yield = (100-price)/price * 360/days
      = (100-98)/98 * 360/90

This is a simple annualization, not a compounded forecast or a guarantee that the same return can be repeated throughout a year. The worked result is independent arithmetic rather than an authored Zoho execution.

The public Zoho worksheet includes these complete examples:

The date differences are 70 and 364 actual days. Independent checks give (100-5)/5*360/70 = 97.7142857143 and (100-50)/50*360/364 = 0.989010989011, matching the displayed precision. Published TBILLYIELD demonstration.

The first published price is unusually low; its raw result is about 97.714, which would display as about 9,771.43% with percentage formatting. Do not read that raw number as 97.714%. The example identifies vendor behavior, not a realistic investment recommendation.

These observations support the displayed dates and price-based 360-day model. They do not resolve every leap-day, zero-interval or exact maturity-limit boundary.

For January 1 to June 30, 2025, the actual difference is 180 days. At price 97, the independent yield is (3/97)*(360/180) = 0.0618556701030928, or approximately 6.18556701%.

Changing the size of a holding does not change this quoted yield when price scales consistently. For example, paying 9,700 for par 10,000 corresponds to the same price 97 per 100. Use the per-100 quote in the function, not 9,700.

For positive price and a positive date interval, a lower price implies a higher model yield. This direction check is useful when comparing two quotations for the same maturity. Different remaining intervals require their own day counts; price alone does not determine the annualized figure.

In the 90-day example, a discount rate of 8% produces price 98 under the independently checked TBILLPRICE model. TBILLYIELD’s reference is about 8.1633% because the gain is measured against price 98 rather than par 100.

The independent reconciliation does not claim an executed round trip in Zoho. It shows why the two rates answer different questions and should not be substituted merely because both are annualized percentages.

Zoho lists #NUM! for negative issue_price, settlement after maturity, or maturity more than one year after settlement. The cited wording says negative, not nonpositive; an exact price-zero error is therefore not asserted here. The mathematical model divides by both price and day count, so zero values require special attention rather than an invented runtime guarantee. Official error conditions.

Use DATE to make the intended dates unambiguous. This guide does not establish text coercion, fractional-date behavior, exact one-year boundaries or actual transaction charges.

Official help and the public vendor demonstration were checked October 18, 2026. No authored Zoho workbook or public screenshot was produced. The worked outputs are independent calculations, and the labelled vendor rows are read-only published observations. Introduction version, mobile parity and historical lifecycle are not established by these sources.