Lay the carpet upside down on a flat, workable surface such as concrete. If the carpet is rolled up, unroll it to suit your dimensions.
Measure the carpet to fit the area that you wish to cover. Add about four inches around the sides to make room for error.
Mark a line on the carpet to follow as you cut. You can use a marker to mark your dimensions.
Place a piece of wood such as a 2 x 4 directly underneath the carpet along your marked cutting line. This will ensure that you don't scratch the surface that you're working on or dull the utility knife.
Cut along the line as straight as possible with a utility knife or carpet shears. Ensure that you cut away from your body to reduce the possibility of physical injury.
Measure the area in which you wish to place the rug. Typically, area rugs can be too large for some living or dining rooms.
Flip the rug over and lay it on a flat, workable concrete surface and mark your measurements on the back of the rug.
Place a 2 x 4 underneath the rug directly along the lines you need to cut. This reduces scratching on your concrete surface
Cut the rug along your measured lines with a utility knife or carpet shears. Ensure that you follow a straight line to reduce ripples.
Apply white or clear craft or PVA glue with a paintbrush to the side of the freshly cut rug. This will prevent it from fraying.