Finishing
Sandpaper Grit Progression Selector
Pick the right grits for your sanding job — from rough stock removal to final finishing — and don't waste steps.
Calculator
Raw hardwood / Between coats / Refinishing
Smooth stain-ready / Poly-ready / Glass-smooth
Hardwood / Softwood
What makes this different
Most grit charts list 'start at 80, finish at 220'. This one asks what you're sanding (raw wood, between coats, refinishing an old finish) and your target smoothness, then generates a 3–5 step progression that skips unnecessary stages.
Who it's for & when to use it
Planing, prepping raw lumber, between-coat sanding, refinishing furniture.
How to use
- Enter the dimensions of your material or the parameters of your project.
- Adjust the optional knobs (waste factor, kerf, planer allowance) to match your shop practice.
- Click Calculate and read the output. Use the per-item breakdown for ordering, the totals for budgeting.
- Compare the result to your lumber yard's quote — the effective $/BF column is the apples-to-apples number.
Formula: Each grit removes the scratch pattern of the previous grit. Skipping more than 1 step leaves visible scratches.
Notes & tips from the shop
- Power sanding can skip a step because the scratch pattern is more uniform. Hand sanding typically needs every step.
- For between-coat poly, 220–320 is plenty. For stain prep, 150–180 is often enough — finer grits close the grain and reduce stain absorption.
- Replace sandpaper when it stops cutting. Old paper polishes wood instead of cutting it.
Frequently asked questions
Why does higher grit not always mean smoother?
Very fine grits (> 600) burnish the surface and can prevent stain or glue adhesion. Stop at 220 for stain prep.
Can I skip grits if I'm in a hurry?
Yes for rough work, no for finishing. Each grit exists to remove the scratch pattern of the previous one — skipping too far leaves visible marks.
What's the difference between stearated and non-stearated?
Stearated papers have a dry lubricant; they cut faster and clog less, ideal for bare wood. Non-stearated is better for between-coat sanding.
Limitations
Grit progressions are general guidance; final choice depends on the wood's response and your eye.
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