A grading scale is the numerical framework used by a third-party grading service to express the condition of a collectible. The two dominant systems in collecting are the 1–10 trading-card scale (with half-point increments) and the 1–70 Sheldon scale used by all major coin graders. Comic books are graded on a 0.5-step 0.5–10 scale by CGC and CBCS, and watches and other items are typically described in qualitative tiers (mint, excellent, very good, good, fair) rather than a single number.

Each scale is governed by published criteria and applied by trained graders, but the criteria are interpreted by humans and the same item submitted twice can occasionally come back at different grades. Crack-and-resubmit strategy exists in every category as a result.

Most major graders use a 10-point scale, with whole-point grades for general use and half-point or quarter-point increments for finer distinctions. PSA grades on whole points 1 through 10. BGS uses half-point increments and adds subgrades for corners, edges, surface and centring. CGC similarly grades in half-point increments. Lower grades 1 through 5 cover damaged through played condition; 6 and 7 cover light wear; 8 is near-mint-mint; 9 is mint; 10 is gem mint or pristine. See our grading guide for hands-on application.