PSA fundamentals · 8 min read · Updated 7 May 2026

PSA centering requirements: the 55/45 rule, and how to measure yours

PSA centering requirements are the only sub-grade where PSA publishes hard numerical thresholds - which means a deterministic measurement at home gets you a deterministic answer. Centering is also the easiest sub-grade to fail, the easiest to assess at a glance, and the single biggest predictor of whether your card returns PSA 9 or PSA 10. This guide walks you through the published thresholds, the actual measurement maths, and how to apply the worst-axis rule that catches most collectors out.

PSA centering requirements at a glance

For the front of the card: PSA 10 needs 55/45 or better on both the left/right and top/bottom axes. PSA 9 allows up to 60/40. PSA 8 allows up to 65/35. PSA 7 allows up to 70/30. The worse axis is your ceiling. Back centering is judged at one band looser than the front.

Front centering thresholds (PSA 7-10)

• PSA 10: max 55/45 on both axes.
• PSA 9: max 60/40.
• PSA 8: max 65/35.
• PSA 7: max 70/30.
• Worse than 70/30: PSA 6 or below.

Both axes - left/right and top/bottom - must meet the threshold. The worst axis is the ceiling. So a card that's 53/47 L/R but 64/36 T/B is capped at PSA 8, regardless of how clean the corners and surface are.

What the 55/45 rule actually means

The 55/45 rule is shorthand for PSA 10 centering: the inner artwork frame must sit between 45% and 55% of the way across the card on both axes. Said another way: the smaller margin on either axis must be at least 45% of the combined margin width. A 50/50 card is perfectly centred; 55/45 is the worst centering allowed for gem mint.

How to measure Pokemon card centering at home

1. Use a ruler with millimetre markings, or callipers if you have them.
2. Measure the inner artwork frame to each outer card border, on each axis - top, bottom, left, right.
3. Compute the ratio: min / (min + max) × 100. That's your smaller-margin percentage.
4. The ratio is expressed as (100 - x) / x where x is the smaller margin.

Example: top margin 2.8mm, bottom margin 3.4mm → 2.8 / (2.8 + 3.4) × 100 = 45.2 (so the ratio is 54.8 / 45.2). Just inside PSA 10 on that axis.

Worked examples: PSA 10, 9, and 8 centering

How CardPreGrading measures centering to 0.1mm

We use a deterministic geometric algorithm:

1. Detect the outer card border via background-subtraction contour analysis.
2. Detect the inner artwork frame via Sobel-gradient edge detection.
3. Compute four margins; output L/R and T/B ratios to one decimal place.

It's the same maths a PSA sub-grader does with calipers - just faster, and without human eye-strain. The output is auditable: every measurement traces back to the detected edges, not a black-box model. See how it works for the full pipeline.

Front vs back centering rules

Most Pokemon cards have very consistent backs because the Pokemon back is machine-printed at high precision. The bigger variance is the front. PSA does measure both, but back centering is judged at one band looser - so a back at 65/35 is fine for PSA 9 (where 60/40 is the front threshold). Back centering only caps your overall grade when it's severely off.

Cards right at the threshold

The closer to a boundary, the more grade variability you'll see across submissions. A 60/40 card will grade PSA 9 most of the time, but PSA 8 when a sub-grader's judgement goes the other way. We reflect this in our verdict by lowering confidence near band boundaries - because the underlying outcome is genuinely uncertain.

Practical rule: if your worst-axis ratio is within 1 percentage point of a threshold, treat the next-lower grade as a real possibility. Don't bet a $30 PSA fee on a coin flip.

Should I grade an off-centre Pokemon card?

Off-centre cards (worse than 60/40) almost never deserve PSA submission unless the raw value is so high that even a PSA 7 or 8 outcome is in profit. For modern cards, that usually means raw value $200+ before an off-centre card breaks even. For vintage Pokemon, the bar is much lower because PSA 7 vintage Charizard still sells for hundreds.

For the full submit/skip framework, see should I grade my Pokemon card?