While there are several types of laser levels, the basic idea is that the tool emits a laser line that is straight and level, with a few advantages over hand sighting levels. One advantage is the length of the line. The line projected by laser levels can reach 15-60 feet or more, whereas most levels that the casual user will have on hand will be six feet long at the most. That means you would normally have to repeatedly shift the level along the wall and make more markings to maintain a continuous line. In addition, that line has to be marked, and presumably, that means at some point it will probably need to be erased, painted over, or otherwise removed. Another advantage is that some models adhere to vertical surfaces, such as walls, so you can attach them and move on with your project with your hands free. For the average weekend do-it-yourselfer, these can be useful with projects like hanging pictures or shelves. If you're a little more ambitious, you may want a laser level that emits two lines, perpendicular to one another. These are really handy for jobs like laying tile and installing cabinets.



What are the downsides to a laser level? For one thing, they run on batteries, so they can run out of power at inopportune times. Also, laser beams can be very harmful to your vision – you should never look directly into one – so their strength is regulated. Laser levels use a low strength laser beam. What that means when you are working with a laser level is that they may be difficult to see and are not usually able to be used outdoors. You can purchase laser glasses that help to filter out other light besides your laser beam, but you will also need to weigh that additional cost if it is an option you choose. Laser glasses will allow you to see your laser line more clearly in bright light and over longer distances.

From a cost perspective, laser levels can be quite cost effective and actually cost about the same as high quality hand sighting levels.