Carpentry levels come in many forms. Levels are definitely essential carpentry tools. Without them, you would never know if the structure you are building is level or plumb. There are as many ways to level a structure as your imagination will allow.
For instance, you could use a clear plastic tube and partially fill it with water. Hold it in a U-shape, and the height of the water on one end is level with the height of the water on the opposite end. If you use your imagination, you can see how this could be used if a store-bought level wasn't available.
Fortunately, there are plenty of inexpensive carpentry levels to choose from without resorting to the plastic tube. There are several of the old style carpenter's levels that have been around for many years.
They come in several sizes, but the most common are the 24-inch and the 48-inch. You can level most projects with a combination of those two. The 48-inch level is good for leveling deck joists or plumbing wall studs, and the 24-inch is great for leveling things where a 48-inch level may not fit (like a window sill or door header).
For projects where you are trying to level a large deck or structure, a transit level is perfect. I have used a transit level many times when a 48-inch level is too small.
Suppose you are trying to level the frame of a multi-tiered deck. Leveling it with a standard bubble level would not be practical. With a transit level, you can level structures across large spans with a great deal of accuracy by simply rotating the scope.
In these modern times, carpentry levels span many technologies. There are several levels to choose from for almost any application.
There are laser levels for installing things like drop ceilings on large commercial projects. There are digital levels - levels with a digital readout instead of a bubble).
There are torpedo levels (like the orange one shown at the top of this page) for leveling small objects.
There are magnetic levels for plumbing metal studs. These levels stick to the metal studs so that you don't have to hold them in place while you are screwing them to the upper and lower channel.
There are 8-foot levels for plumbing residential walls - they typically span the bottom and top plates. These levels also work great when leveling objects that are further apart where a four footer won't work.
There are also many more specialized levels that are designed for very specific applications. There are even level applications designed for use with mobile devices, such as the iPhone. And there's the very impressive digital level which I will most certainly purchase soon!
As mentioned earlier, the 24-inch and the 48-inch are the most common and are considered by myCarpentry to be on the list of essential carpentry tools. If you are a deck builder or builder of small to large homes, a transit level is a must.
*Most of the images on this page were obtained from Amazon.com for the purpose of promoting products sold on Amazon.com.