How to Choose the Right Sandpaper Grit for Your Project (2024)

Sandpaper is used in many home improvement projects, from refinishing furniture to smoothing drywall. To avoid damage and inefficiency while working with your surface, it's important to select the right sandpaper grit. Choosing the appropriate sandpaper starts with understanding sandpaper grade, grit numbers, and how to determine the grit and grade your project calls for.

What Is Sandpaper Grit?

Sandpaper grit is a number that determines the coarseness of sandpaper. In other words, this number determines how aggressively the sandpaper will sand a given material. Lower numbers signify coarser grit and higher numbers indicate finer grit. Coarser sandpaper sands material more aggressively than finer sandpaper.

Contrary to popular belief, the number itself doesn't refer to the number of abrasive particles on the paper, but rather the number of holes per inch on the screens used to sift the particles in the manufacturing process. The more holes per inch in the screen, the smaller the holes. This results in smaller abrasive particles distributed on the paper. The fewer holes per inch, the larger the holes, which results in larger abrasive particles on the paper.

Sandpaper Grit Vs. Sandpaper Grade

So what is the difference between sandpaper grit and sandpaper grade? Sandpaper grit is a number rating based on the manufacturing process, such as 80, 120, and 220. Sandpaper grade is a general class of sandpaper coarseness, including coarse, fine, very fine, and extra fine. Each sandpaper grade consists of a range of grits.

How Sandpaper Works

Regardless of whether you're hand-sanding, using a power sander, or using coarse sandpaper versus fine sandpaper, all sandpaper works the same way. The grit consists of abrasive particles attached to a backer, often made from paper or cloth. Each abrasive particle makes a cut as the sandpaper moves on the material's surface. The sandpaper grit number will determine how many cuts there are and how deep each cut is. Finer sandpaper grits make cuts that are hardly visible to the naked eye, while coarser grits leave deep gouges that can be unsightly.

Because of this, the sanding process usually involves starting with lower grits and advancing to higher grits. Each increasing grit number will smooth the scratches left by the former grit, resulting in a surface that's smooth to the touch and without visible scratches.

How to Choose the Right Sandpaper Grit

Choosing the right sandpaper grit depends on your project, material, and what you need the sandpaper to accomplish. More than likely, you'll need to use several incremental grits.

For example, if you're refinishing a piece of wood furniture, you'll start with a coarse grit like 80 to remove the finish and smooth any imperfections. Next, you'll advance to a finer grit like 100 or 120 to smooth the scratches left behind by the 80-grit sandpaper. From there, your next grit will be determined by your finish. If you plan to paint the piece or apply a film finish such as polyurethane, it's likely ready to go. If you plan to apply a penetrating finish like a stain or penetrating oil, advance to 150 to 220 grits.

Consider the Wood Finish

For wood projects, the right sandpaper grit or set of incremental grits is determined by the nature of the finishes themselves. Finishes that sit on the wood's surface (paint, polyurethane, lacquer, etc.) hide the fine scratches left by 120-grit sandpaper. However, penetrating finishes (stain, Danish oil, penetrating oil, etc.) soak into the scratches, highlighting their visibility.

Starting with too high of grit will result in wasted time and effort. Plus, you'll burn through sandpaper quickly trying to remove finishes or smooth rough material with higher-grit sandpaper. However, starting with too low of grit can damage your project in a way that is hard or impossible to undo. For example, you can quickly ruin wood details on furniture by eating through them with coarse sandpaper.

Sandpaper Grit Chart

Reference the table below to choose your start and end grit, then advance through the grits between the two for the best results and most efficient sanding.