This article describes the formula syntax and usage of the DISC function (function: A prewritten formula that takes a value or values, performs an operation, and returns a value or values. Use functions to simplify and shorten formulas on a worksheet, especially those that perform lengthy or complex calculations.) in Microsoft Excel.
Description
Returns the discount rate for a security.
Syntax
DISC(settlement, maturity, pr, redemption, [basis])
Important Dates should be entered by using the DATE function, or as results of other formulas or functions. For example, use DATE(2008,5,23) for the 23rd day of May, 2008. Problems can occur if dates are entered as text.
The DISC function syntax has the following arguments (argument: A value that provides information to an action, an event, a method, a property, a function, or a procedure.):
 Settlement Required. The security's settlement date. The security settlement date is the date after the issue date when the security is traded to the buyer.
 Maturity Required. The security's maturity date. The maturity date is the date when the security expires.
 Pr Required. The security's price per $100 face value.
 Redemption Required. The security's redemption value per $100 face value.
 Basis Optional. The type of day count basis to use.
Basis 
Day count basis 
0 or omitted 
US (NASD) 30/360 
1 
Actual/actual 
2 
Actual/360 
3 
Actual/365 
4 
European 30/360 
Remarks
 Microsoft Excel stores dates as sequential serial numbers so they can be used in calculations. By default, January 1, 1900 is serial number 1, and January 1, 2008 is serial number 39448 because it is 39,448 days after January 1, 1900.
 The settlement date is the date a buyer purchases a coupon, such as a bond. The maturity date is the date when a coupon expires. For example, suppose a 30year bond is issued on January 1, 2008, and is purchased by a buyer six months later. The issue date would be January 1, 2008, the settlement date would be July 1, 2008, and the maturity date would be January 1, 2038, 30 years after the January 1, 2008, issue date.
 Settlement, maturity, and basis are truncated to integers.
 If settlement or maturity is not a valid serial date number, DISC returns the #VALUE! error value.
 If pr ≤ 0 or if redemption ≤ 0, DISC returns the #NUM! error value.
 If basis < 0 or if basis > 4, DISC returns the #NUM! error value.
 If settlement ≥ maturity, DISC returns the #NUM! error value.
 DISC is calculated as follows:
where:
 B = number of days in a year, depending on the year basis.
 DSM = number of days between settlement and maturity.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How do I copy an example?
 Select the example in this article. If you are copying the example in Excel Online, copy and paste one cell at a time.
Important: Do not select the row or column headers.
Selecting an example from Help
 Press CTRL+C.
 Create a blank workbook or worksheet.
 In the worksheet, select cell A1, and press CTRL+V. If you are working in Excel Online, repeat copying and pasting for each cell in the example.
Important: For the example to work properly, you must paste it into cell A1 of the worksheet.
 To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Formulas tab, in the Formula Auditing group, click the Show Formulas button.
After you copy the example to a blank worksheet, you can adapt it to suit your needs.

A 
B 
Data 
Description 
January 25, 2007 
Settlement date 
June 15, 2007 
Maturity date 
97.975 
Price 
100 
Redemption value 
1 
Actual/actual basis (see above) 
Formula 
Description (Result) 
=DISC(A2,A3,A4,A5,A6) 
The bond discount rate, for a bond with the above terms (0.052420213 or 5.24%) 

Note To view the result as a percentage, select the cell, and then on the Home tab, in the Number group, click the arrow next to Number Format, and click Percentage.