Card Centering Calculator
Photograph any sports card, front and back. The card is found and straightened, both the cut edge and the printed frame are measured, and the table shows the highest grade PSA, BGS, SGC, CGC and TAG allow on centering alone.
Centering is the ratio of the border widths on opposite sides of a card, and it is the one part of a grade you can measure before you send it away. Add a photo of the front: the card is found, straightened, and both edges are measured for you. Add the back for the grade ceiling each company would allow.
How Graders Interpret Centering
Two Borders, Not One
Centering calculates the ratio between opposite borders. A 60/40 card means one border is 50% wider than the opposite side.
The Worse Axis Determines Grade
Even if left/right is a perfect 50/50, if top/bottom is 65/35, graders cap the overall centering grade based on the worse axis.
Front vs Back Standards
Front centering is strictly scrutinized (e.g. 55/45 for PSA 10), while card backs allow more leeway (up to 75/25 for PSA 10).
Centering Tolerances by Grading Company
| Grading Company | Top Grade (Front) | Top Grade (Back) |
|---|---|---|
| PSA 10 (Gem Mint) | 55/45 both axes | 75/25 |
| BGS 10 (Pristine) | 50/50 both axes | 55/45 |
| BGS 9.5 (Gem Mint) | 50/50 one axis, 55/45 other | 60/40 |
| SGC 10 (Gem Mint) | 55/45 both axes | 70/30 (not published) |
| CGC 10 (Pristine) | 50/50 both axes | 75/25 |
| CGC 10 (Gem Mint) | 55/45 both axes | 75/25 |
| TAG 10 (Gem Mint) | 55/45 both axes | 70/30 |
Frequently Asked Questions
- How is card centering measured?
- Centering compares the border widths on opposite sides of a card. If the left border is 60% of the two side borders added together and the right is 40%, the card is 60/40 left to right. The same is done top to bottom, and graders key their tolerances on whichever of the two numbers is worse.
- What centering does a PSA 10 need?
- PSA allows up to 55/45 on both axes on the front of a card and up to 75/25 on the back for its top grade. A card outside that cannot reach a 10 on centering alone, however clean its corners and surface are.
- Is this centering tool free?
- Yes, and there is no limit on how many cards you measure. The photograph is read in your own browser and is never uploaded.
- Why does my card measure differently each time?
- Almost always the photograph. The tool finds the card and flattens it, so a few degrees of rotation or tilt do not matter, but a card shot from well off to one side has borders that are wider on the side nearer the lens, and no flattening can fully undo that. Shoot from directly above, with the whole card in frame and even light.
- Does the back matter?
- Yes. Every company grades the back more loosely than the front, but a back outside its tolerance still caps the grade. Add both photos and the table shows the ceiling for each side and for the card as a whole.
- Does good centering guarantee a high grade?
- No. Centering sets a ceiling. Corners, edges and surface are judged separately and can only take a card below that ceiling, never above it.