the present invention relates to a method and apparatus for allowing the accurate calculation of the minimum number of linear feet of carpet which must be cut from a standard width roll and delivered to an installation site to completely , properly and efficiently cover the floor at the installation site . the present invention provides a length of measurement tape which is scaled in width to the width of a standard roll of carpet . the measurement tape is perforated at increments along its length and width , and includes indicators of carpet grain direction and pattern repetition intervals along its length and / or width .