Installing carpet can be a bear, especially in an oddly shaped room. With a step by step approach, though, you'll come out the other side still sane with a new sense of accomplishment.
Step 1 - Measure the Space
It seems obvious, but some people try to skip this step—don't. Measure the floor space where the carpet will go, and write these measurements out on a piece of paper (it doesn't have to be to scale).
Most carpets come in 12-foot widths, and when you cut a carpet to fit a room that demands something smaller than that, the most important thing to avoid is cutting the carpet too small for one of the dimensions.
Place the end of a tape measure along the edge of the floor and extend it to the other side of the room. Add four inches to the measurement you took and record it. Do this with both the width and the length of the room. If you want to be extra cautious, add six additional inches onto the measurement as an extra insurance policy.
Step 2 - Unroll the Carpet
In a large area—ideally larger than the material with which you're working—unroll the carpet you’re going to cut and place it upside down so the backing faces up. You want to ensure you have enough room to work, so if you don't have access to a large enough interior space, you might want to consider trying this outside, in which case you may wish to lay a tarp to protect your future cozy flooring.
Step 3 - Mark the Carpet for Width
Now, mark your carpet at the right measurements width wise so you can cut it to fit in the desired room. Use a tape measure and marker to add lines based off of the measurements you took in step one. Be sure to mark the lines in several places along the carpet to make cutting easier all the way across.
Step 4 - Cut Where Marked
Now, use a utility knife or carpet cutters to cut where you added the markings. Press down as you cut across the carpet. Keep in mind that the tool you use to cut the carpet should be very sharp, earning the need to wear safety gloves if desired out of caution.
Step 5 - Mark the Carpet for Length
Now, repeat step three but mark the carpet for length this time per your original measurements.
Step 6 - Cut Where Marked
Again, cut where you market the carpet all the way across for length.
Step 7 - Place the Carpet In Its New Home
Now, bring the carpet to the room it will end up in if you were working in an alternate room. Unroll the carpet and place one side of it flush against the wall. Most likely, there will be extra slack on the carpet from where you added the four inches onto your original measurements. For now, don’t worry about the extra carpet and secure the carpet to the floor along the edge you matched up exactly to the wall.
Step 8 - Crease the Excess
Use a hookbill knife on top of the carpet where it meets the wall on one side where there is excess material. This tool will look like a metal hook. Press down firming with the hook to create a crease along the length of the wall on every side.
Step 9 - Trim the Carpet
Now, place a carpet wall trimmer on the floor with the blade facing towards the wall. The trimmer should be placed as close to the wall as you can. Press the device forward to cut along the creases that you created on each side.
Step 10 - Secure the Carpet
Now that your carpet is trimmed to size, secure it on each side and your carpet will be fully installed, contributing to the completion of your room.
After you have completed this process, you may feel compelled to discard the carpet scraps that you cut off to make this item fit in the room of your choice. Luckily, there are actually alternate uses for carpet scraps.