Sanding Grit Progression Calculator
Skipping Grits Leaves Scratches Behind
Sanding works by having each successive grit remove the scratch pattern left by the one before it — jump from 80 grit straight to 320 and the finer paper can't cut deep enough to erase the coarser scratches, leaving them visible under a finish. Working through a proper progression, rather than skipping steps to save time, is what actually produces a smooth, even surface.
The Standard Progression
This is the standard published woodworking sanding grit sequence. The calculator snaps your requested starting and ending grit to the nearest values on this standard scale, then returns every step in between as the recommended progression.
Typical Use Case by Grit Range
| Grit range | Typical use |
|---|---|
| 40–60 | Aggressive stock removal, leveling rough surfaces |
| 80–120 | General surface prep, removing mill marks and tool marks |
| 150–220 | Final sanding before stain or finish |
| 240–400 | Between-coat sanding of finishes |
| 600+ | Polishing finishes, rubbing out a top coat |
A common rule of thumb is not to skip more than roughly one grit "step" at a time (for example 80 to 120 to 150), which is why the standard progression above has closely spaced steps in the coarser range and wider gaps once scratches are already fine.
Where This Matters
- Preparing wood for staining — stain highlights uneven sanding scratches more than a clear finish does, making a proper grit progression especially important before staining.
- Working with power sanders efficiently — random orbital sanders still need a logical grit progression; the calculator helps plan how many disc changes a sanding session actually requires.
- Finishing between coats — light sanding with a fine grit between coats of finish (often 320–400) knocks down dust nibs and improves adhesion for the next coat.
How to Use This Calculator
- Enter the Starting Grit (for example, 60).
- Enter the Ending Grit (for example, 320).
- Select Calculate to see the recommended step-by-step grit progression.
Related Calculations
Check the joint strength of the piece you're finishing with the Wood Joint Strength Calculator, or verify moisture content before finishing with the Wood Moisture Content Calculator.