agrees Internal Revenue Service: Figuring Gross Profit Internal Revenue Service: Figuring Gross Profit sales tax Internal Revenue Service: Figuring Gross Profit http://www.irs.gov/publications/p334/ch07.html IRS.gov: Figuring Gross Profit Internal Revenue Service: Figuring Gross Profit IRS: Tax Guide for Small Businesses - Figuring Gross Profit Part 7 Figuring Gross Profit IRS.gov: Tax Guide for Small Business, Figuring Gross Profit Part 7 Figuring Gross Profit IRS Publication 334: Figuring Gross Profit sales tax