Guide · For collectors & beginners

How to grade trading cards, explained simply.

Grading isn't magic — it's four measurable axes: centering, corners, edges and surface. Here's how each one works, and how to evaluate your own cards before sending them off.

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Beginner-friendlyUpdated 2026Pokémon · Sports · MTG · YGO
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How it works

How to grade a trading card by the four axes

  1. Set up bright diffused light

    Use natural daylight near a window, or a soft diffused indoor light. Avoid overhead bulbs that create direct glare on holos or hide surface flaws.

  2. Measure the centering by eye or ruler

    Hold the card straight-on. Compare left/right and top/bottom border widths. 55/45 or better is required for PSA 10; 60/40 caps the grade at 8.

  3. Inspect each corner under magnification

    Use a jeweler's loupe or your phone's macro camera. Look for whitening, rounding, or fraying on any of the four corners. Even one whitened corner drops the grade.

  4. Tilt the card to check edges and surface

    Hold the card under direct light and tilt it slowly. Edge wear shows as silvering on holo edges; surface flaws show as scratches, print lines, or holo scratches.

  5. Combine your read into a likely grade

    A clean card across all four axes = PSA 9 or 10. One axis at 8 caps the grade at 8. Two axes at 8 caps at 7. Use this read to decide whether PSA submission is worth it.

The four grading axes

Centering, corners, edges, surface.

Every professional grader uses these four axes. If you can evaluate them yourself, you can predict your card's grade.

Centering

The card's image relative to its borders. Measured as L/R and T/B ratios. 55/45 or better is required for a PSA 10.

Corners

Sharpness, whitening, and rounding. A single whitened corner can drop a PSA 10 to a 9. Look closely under good light.

Edges

Chips, dings, and bevel wear along the four edges. Holo edges show silvering — check under direct light.

Surface

Scratches, print lines, holo scratches and orange peel. Even tiny surface flaws move the needle from a 10 to a 9.

The basics before you grade.

Card grading is a 1–10 scale (PSA, CGC) or 1–10 with 0.5 increments (BGS). A PSA 10 (Gem Mint) is essentially flawless. A PSA 9 (Mint) has very minor wear. The drop from 9 to 8 is much bigger than from 10 to 9 — most of the value lives at 9 and 10.

How to set up for self-grading

The 10-second self-grade checklist

When to use AI pre-grading instead

Self-grading by eye is fine for a handful of cards, but it's slow and inconsistent. AI pre-grading measures the same four axes pixel-by-pixel and gives you a calibrated prediction in seconds. Use self-grading for first-pass triage, and SnapGrade for the final go/no-go before PSA.

Common questions

Questions we hear all the time.

Can I learn to grade my own cards as well as PSA?
You can get close on centering and obvious wear, but professional graders catch micro-flaws that the human eye misses. AI pre-grading splits the difference — it's far more consistent than your eye, far cheaper than PSA, and calibrated against actual returns.
What's the easiest grading axis to learn first?
Centering — it's purely measurable. Hold a ruler or use a phone app, and you can L/R measure within 5 minutes of practice.
How does AI compare to self-grading?
Self-grading: free but slow and inconsistent. SnapGrade: $1–$2/card, pixel-precision on all four axes, calibrated against 412 verified PSA returns.
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