Free tool
Card centering calculator for the front and back.
Enter the four border widths on each side of a card. You get the left/right and top/bottom ratios and the score each side meets on CCA's published centering scale.
Centering calculator
Enter each border width, from the card's cut edge to the printed frame, in any one unit (millimetres, 1/64 inch or pixels).
Front
Waiting for four borders.
Back
Add the back to include it.
Centering subgrade on CCA's scaleFront only until you add the back
-
An estimate of one subgrade on CCA's published scale, not a grade. Centering is one of four subgrades, and other graders publish their own tolerances. Nothing you enter leaves your browser.
How do I measure card centering?
Measure each border from the card's cut edge to the printed frame, on all four sides, using one unit throughout.
Any of these works, from simplest to most precise:
- A millimetre ruler and a magnifier, reading each border to the nearest half millimetre.
- Digital calipers, closed gently on the border so the card is not marked.
- A flatbed scan at a fixed resolution, then the pixel distance in any image editor. Pixels are a unit like any other; the ratio is the same.
Measure at the narrowest point of each border. If the print is tilted against the cut, one corner will be tighter than the other end of the same edge, and that tighter reading is the one that counts. On full art or borderless designs, use a printed line that runs parallel to the edge, and treat the result as rougher.
How is a centering ratio calculated?
Divide the wider border by the two borders added together. The result and its remainder make the ratio, such as 55/45.
Example: a left border of 2.0 mm and a right border of 1.5 mm. 2.0 ÷ (2.0 + 1.5) = 57.1%, so the card is 57.1/42.9 left to right. Do the same for top and bottom. The card is scored on the worse of the two axes, because a card that is perfect side to side but off top to bottom is still off center.
What ratio does a card need for a 10 in centering?
On CCA's scale a front needs 55/45 or better and a back needs 60/40 or better.
| Score | Front (worse axis) | Back (worse axis) |
|---|---|---|
| 10 | 55/45 or better | 60/40 or better |
| 9.5 | 57/43 or better | None |
| 9 | 60/40 or better | 65/35 or better |
| 8 | 65/35 or better | 70/30 or better |
| 7 | 70/30 or better | 75/25 or better |
| 6 | 75/25 or better | 80/20 or better |
| 5 | 80/20 or better | 85/15 or better |
| 4 | 85/15 or better | 90/10 or better |
| 3 | 90/10 or better | 95/5 or better |
| 2 | 95/5 or better | Worse than 95/5 |
| 1 | Worse than 95/5 | None |
The back ladder is one full level easier than the front, and 9.5 is the only half step. This is the same scale published on the CCA grading standards page and used by our graders.
How do the front and back combine?
Each side gets its own score, and the centering subgrade is the average of the two.
Halves round down, except an exact 9.5, which stands. A front 10 with a back 8 is a 9; a front 10 with a back 9 is a 9.5; a front 9 with a back 8 is an 8. Without a back measurement the calculator shows the front score alone.
Does centering decide the overall grade?
Centering is one of four subgrades, with corners, edges and surface. It can hold a card back, but it cannot carry it.
The overall CCA grade weights surface the most and is capped relative to the weakest subgrade, so a centering score well below the rest of the card limits the overall grade. A perfectly centered card with a scratched surface still grades on the scratch. The full formula is on the grading standards page.
Do other graders use the same centering tolerances?
No. Each grader publishes its own centering tolerances, and they have changed over time.
A ratio that meets a 10 on CCA's scale may not meet a 10 elsewhere, and the reverse. Read the current standards on each grader's site before you rely on a number from a forum post. Our PSA vs CGC comparison covers how the two larger graders differ more broadly.
What does measured centering look like on a real slab?
CCA certs show the measured ratios for the front and back, with the cut edge and printed frame drawn on the card.
Four certs from the public record
- Cert #216, 1999 Jungle 1st Edition Pikachu: 51/49 by 53/47 on the front, a 10 in centering.
- Cert #144, 30th Celebration Pikachu: 58/42 left to right, a 9 on the front.
- Cert #92, 1990 NBA Hoops Michael Jordan: 51/49 on the front and 64/36 on the back.
- Cert #25, 2026 Bowman Jacob Misiorowski: 50/50 side to side but 65/35 top to bottom.
For the method behind these numbers and what 200+ graded cards showed, read card centering explained.
About this calculator
The result is an estimate of one subgrade, not a grade. Hand measurements are less precise than a 300 DPI scan, so a card that sits right on a threshold can land either side of it. Everything runs in your browser; nothing you enter is uploaded or stored.Keep reading
Ready when you are
Centered well? Get it measured on a 300 DPI scan.
CCA certs publish the measured centering with four subgrades. $8 per card on Bulk with 10 or more, or $10 per card on Standard.