How to Cut a Door Mat to Size

Measure the width of your door opening to determine the optimal length for your door mat. Measure the space between the end of the door and the wall, if you want to place a door mat inside at a door that sits in a corner. Double this inch measurement and add the width of the opening to determine the maximum size for your door mat.

Measure the width of the door mat to ensure the mat will fit onto your door step or placement site. If the mat will not fit, measure the site for the maximum door mat width you can place in the area.

Use the measurements from the previous steps, tape measure, Carpenter's square and chalk line to draw cutting lines onto the door mat. For door mats containing text or designs, you must center the cutting lines to salvage the designs. Measure inward on all sides, as necessary, and make small marks to guide how much mat to remove outside of the design. Stretch the chalk line straight across the mat, between marks and pluck the line to create straight, non-slanting lines to guide you as you cut the mat.

Fold the door mat in half width and length-wise, making small chalk marks to signify the middle of each side of the door mat. Reference those marks as you draw the cutting lines for the door mat. Make the cutting lines for the door mat length first, and then make the lines for the width of the mat, if necessary.

Score the cutting lines by dragging the utility knife across the lines. Do not attempt to cut straight through the mat immediately, as this will produce staggered and jagged cuts. Instead, repeatedly drag the utility knife across the lines slowly until you remove the excess parts of the door mat completely. Cut off one side at a time instead of attempting to cut out the excess in a frame shape.

Apply a thin line of silicone sealant to the cut edges of the door mat. This helps to prevent the door mat from fraying and any fibers from unraveling or falling loose. Apply the sealant slowly and smooth it down with your finger. Allow the sealant to dry before sitting the door mat back down for use.