Microsoft KB Archive/89717

= Microsoft Knowledge Base =

Excel: ATP Definition: ACCRINT
Last reviewed: January 30, 1996

Article ID: Q89717

The information in this article applies to:


 * Microsoft Excel for Windows 95, version 7.0
 * Microsoft Excel for Windows, versions 4.0, 5.0
 * Microsoft Excel for the Macintosh, versions 4.0, 5.0

SUMMARY
The versions of Microsoft Excel listed above provide a set of special analysis tools called the Analysis ToolPak. This is part of a series of articles that provides information on the underlying formulas used in the Analysis ToolPak functions.

This article covers the ACCRINT function.

MORE INFORMATION
The ACCRINT function returns the accrued interest for a security that pays periodic interest. The function is based on the following formula:

Accrued Interest = P*(R/M)*(summation(Ai/NLi) for i=1 to NC),

where,

Ai = Number of accrued days for the &quot;i&quot;th

quasi-coupon period within odd period, M = Number of coupon periods per year, NC = Number of quasi-coupon periods that fit

in odd period and if this number contains a fraction, round it up to the next whole number, NLi = Normal length in days of the &quot;i&quot;th

quasi-coupon period within odd period, P = Par value (principal to be paid at maturity), R = Annual interest rate as decimal.

In determining the accrued interest for long coupon periods, the number (NC) of quasi-coupon periods must be calculated. This is done by working backwards from the long coupon's interest payment date and adding together the number of standard coupon periods that would fit in the long coupon. The result is then rounded up to the next whole number. For example, between the issue date for 1/1/91 and the first coupon date of 9/1/91 there are 1.5 six month periods or 2 quasi- coupon periods. Therefore, NC would equal 2.

The term &quot;quasi-coupon period&quot; is used to represent the length of the coupon period that is standard for the security (for example, semi- annual or annual). Thus, a municipal bond with nine months for its first coupon period has two quasi-coupon periods, each with a length of 180 days.