    <SEC-DOCUMENT>0001564590-22-014930-index.html : 20220420
    <SEC-HEADER>0001564590-22-014930.hdr.sgml : 20220420
    <ACCEPTANCE-DATETIME>20220420162525
    ACCESSION NUMBER:		0001564590-22-014930
    CONFORMED SUBMISSION TYPE:	DEFA14A
    PUBLIC DOCUMENT COUNT:		3
    FILED AS OF DATE:		20220420
    DATE AS OF CHANGE:		20220420

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			EXPONENT INC
    		CENTRAL INDEX KEY:			0000851520
    		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-MANAGEMENT CONSULTING SERVICES [8742]
    		IRS NUMBER:				770218904
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		DEFA14A
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	000-18655
    		FILM NUMBER:		22838348

    	BUSINESS ADDRESS:
    		STREET 1:		EXPONENT INC
    		STREET 2:		149 COMMONWEALTH DRIVE
    		CITY:			MENLO PARK
    		STATE:			CA
    		ZIP:			94025
    		BUSINESS PHONE:		650-326-9400

    	MAIL ADDRESS:
    		STREET 1:		EXPONENT INC
    		STREET 2:		149 COMMONWEALTH DRIVE
    		CITY:			MENLO PARK
    		STATE:			CA
    		ZIP:			94025

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	FAILURE GROUP INC
    		DATE OF NAME CHANGE:	19930831
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>DEFA14A
    <SEQUENCE>1
    <FILENAME>expo-defa14a_20220420.htm
    <DESCRIPTION>DEFA14A
    <TEXT>
    Document 1 - file: expo-defa14a_20220420.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>2
    <FILENAME>gdtfga2ewjsn000002.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 2 - file: gdtfga2ewjsn000002.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>3
    <FILENAME>gdtfga2ewjsn000001.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 3 - file: gdtfga2ewjsn000001.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>