Guide

How angle grinder disc calculators work

Plain-language guide to sizing a corded angle grinder from needed disc diameter, the 4.5 / 5 / 7 in ladder, RPM matching, and when the answer is NO_MATCH.

What this tool answers

You need a first-pass corded angle-grinder size before buying. Enter needed disc diameter in inches. The calculator names the smallest class on this site’s ladder — 4.5, 5, or 7 in — or returns NO_MATCH. It is not a material-removal FEA or a cordless battery selector.

Disc size vs RPM

Larger discs usually run at lower no-load RPM. Always match the disc’s maximum RPM rating to the tool. Underspeed discs are safer than overspeed discs — never mount a disc above its rated RPM.

Class ladder on this site

Classes use published VEVOR US corded disc sizes checked 2026-09-10: 4.5 in, 5 in, and 7 in. Matching rule: smallest class where published disc ≥ needed diameter.

When the answer is NO_MATCH

If needed disc exceeds 7 in, this site returns NO_MATCH. Typical next steps: a larger industrial grinder, a cutoff saw, or a different process. Do not force a 7 in consumer grinder past this screen.

Sources

VEVOR US angle-grinder product pages for disc-size claims (checked 2026-09-10). Consumer practice matching disc RPM to tool RPM. Safety framing follows common manufacturer warnings on guards and PPE.

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