Measuring your rooms for carpet is not that difficult. Even if your installer is going to do the measuring, it never hurts to have information.
To measure a room you will need a metal tape measure, a paper tablet
and a pencil.
First draw the room. Imagine that you are looking down on the room with the roof off and draw lines for the walls. Mark where the front door and bathroom doors are. You don’t have to draw well or be in proportion.
Take your metal tape measure, put the tape measure on the floor, push the end against the baseboard, run the tape down the length of the room, into the vanity if it is carpeted and take that measure exactly to the inch. Right that measure down next to the line for the wall. Then do the same for the other (shorter) wall. Your installer will take the length of the room and add two inches for a wall and four inches for a wall with a door in it. This allows the installer to “Square the Room” with the carpet and tuck it in under the baseboards to reduce drafts and bug access and create a clean visual edge.
Now measure the two bathroom walls. Where the door is will be called length and the other wall the width. If the width is 6 foot 1 inch or more, then your installer can “Z-CUT” the carpet saving you some of the bathroom carpet waste (2 to 3 foot) for every 2 rooms.