PSA fundamentals · 8 min read · Updated 7 May 2026

The PSA grading scale, explained: from PSA 1 to gem mint 10

The PSA grading scale runs 1 to 10, where every point matters more than the last. The difference between a PSA 9 and a PSA 10 on a chase Pokemon card can be 3-5× the resale value, even though both are described as “mint” to the casual eye. Understanding what each grade actually requires - and what stops a card from getting there - is the difference between submitting profitably and donating money to PSA.

The PSA grading scale at a glance

PSA assigns a numerical grade from 1 (Poor) to 10 (Gem Mint). The grade reflects four sub-grades - centering, corners, edges, surface - rolled up by the head grader. Half-grades (PSA 8.5, 9.5) and letter qualifiers (OC, ST, PD, MK, MC) flag specific edge cases.

What each PSA grade actually means

PSA 10 vs PSA 9: why the gap is so large

A PSA 10 - Gem Mint - requires everything to be near-perfect: centering, corners, edges, surface, and print. Modern Pokemon cards from machine cuts often arrive with one minor centering or edge issue, which silently drops you from 10 to 9. That single flaw can mean the difference between $250 and $45 on a chase card.

Practical collectors think of PSA 10 as the "all four sub-grades clean" tier. PSA 9 allows one sub-grade weakness. PSA 8 allows two. Once you understand the structure, your grade prediction at home gets dramatically more accurate.

PSA centering thresholds (PSA 7-10)

PSA publishes the following centering tolerances for the front of the card:

• PSA 10: 55/45 or better on both axes.
• PSA 9: up to 60/40 on each axis.
• PSA 8: up to 65/35.
• PSA 7: up to 70/30.

Back centering follows the same rules but with looser thresholds (typically one band more forgiving than the front). Both axes must meet the threshold; the worst axis is your ceiling. For the full measurement walk-through, see PSA centering requirements: the 55/45 rule.

How sub-grades work

PSA sub-graders assess four sub-grades on the same 1-10 scale: centering, corners, edges, surface. The overall grade is roughly the weakest sub-grade. A card with a perfect surface but soft corners will grade as the corners suggest. PSA only prints sub-grades on its higher-tier services (PSA Dual Service); standard tier shows the overall grade only.

PSA half grades (PSA 8.5 and PSA 9.5)

PSA does award half-grades for borderline cards. PSA 8.5 means the card is between PSA 8 and 9 - too clean to be flat 8, with one flaw too many for a 9. PSA 9.5 is between 9 and 10, marked with a + on the slab. Half-grades are uncommon (the bulk of submissions resolve to whole numbers) but valuable when a card narrowly misses the next band.

PSA qualifiers: OC, ST, PD, MK, MC

PSA appends letter qualifiers to flag a specific defect that drops the grade:

• OC (Off-Centre) - centering outside the threshold for the assigned grade.
• ST (Staining) - any visible stain on front or back.
• PD (Print Defect) - factory print issues like ink runs or missing dots.
• MK (Marks) - pen marks, scuffs from sleeves, post-print marks.
• MC (Miscut) - the card was physically cut wrong at the printer.

Qualifiers tank resale value because the slab effectively reads "PSA 8 with this specific flaw". Many buyers price qualified cards at 30-50% of the unqualified equivalent.

Pop reports and PSA 10 rarity

For every card, PSA publishes a pop report - the number of copies graded at each level. Modern Pokemon chase cards (Surging Sparks Charizard ex, 151 Mew ex) often have PSA 10 populations of 40-50% of submissions, suppressing the resale premium. Vintage cards from Base Set or Jungle have PSA 10 populations under 1% of total grades, which is why a Base Set Charizard PSA 10 sits at $10,000+.

PSA vs BGS vs CGC: how the scales compare

BGS and CGC use comparable 1-10 scales but with different conventions. BGS issues four sub-grades on every slab and a "Black Label" pristine 10 (10/10/10/10). CGC uses the same numerical scale as PSA with similar centering thresholds but different brand positioning - CGC is dominant in comics and slowly building share in TCG. PSA remains the gold standard for resale on Pokemon, which is why most collectors target the PSA scale by default. ACE Grading uses a near-identical PSA-style scale; see our ACE vs PSA comparison for the UK angle.

Practical takeaway for collectors

• If your card is borderline 9/10, it's often worth submitting because the upside is multiplicative. A clean centering measurement is your best signal.
• If your card is borderline 8/9, the uplift over raw is usually marginal after fees. Pre-grade first.
• PSA 6 and below are almost never profitable to submit on modern cards. On vintage, even PSA 4 can be in profit.
• Use the centering thresholds as your primary filter - it's the only sub-grade with published numerical bands and the only one you can measure deterministically at home.