Card centering calculator for PSA and CGC
Centering is the ratio between opposite borders: 55/45 means the wider border takes 55% of the pair. PSA allows about 55/45 on the front and 75/25 on the back for a 10; CGC asks for 50/50 for a Pristine 10. Measure the borders and see the highest grade your centering allows.
How to measure
- Scan or photograph the card straight on, without a sleeve, with the camera parallel to the card.
- Zoom in and measure each border from the card edge to the start of the frame or artwork, in millimetres or pixels. Use the same unit for all four.
- Repeat on the back. On Pokémon backs, measure to the blue frame.
The calculator takes the worse of the two axes (left-right and top-bottom), as the grading companies do. With 2.2 mm and 1.6 mm side borders, the ratio is 2.2 ÷ 3.8 = 57.9%, so 58/42: PSA 9 under the strict figure and 10 within its approximate range.
Published centering limits
| PSA | Front | Back |
|---|---|---|
| 10 | 55/45–60/40 | 75/25 |
| 9 | 60/40–65/35 | 90/10 |
| 8 | 65/35–70/30 | 90/10 |
| 7 | 70/30–75/25 | 90/10 |
| 6 | 80/20 | 90/10 |
| 5 · 4 | 85/15 | 90/10 |
| 3 · 2 · 1.5 | 90/10 | 90/10 |
| CGC | Front | Back |
|---|---|---|
| Pristine 10 | 50/50 | 50/50 |
| Gem Mint 10 | 55/45 | 75/25 |
| Mint 9 | 60/40 | 90/10 |
| NM/Mint 8 · Near Mint+ 7.5 | 65/35 | not stated |
| Near Mint 7 | 70/30 | not stated |
| Ex/NM 6 | 75/25 | not stated |
| VG/Ex+ 4.5 | 85/15 | not stated |
| Very Good+ 3.5 | 90/10 | not stated |
CGC only states a single 50/50 figure for Pristine, so the calculator applies it to both sides. Where CGC does not state a back limit, only the front is checked.
Limits of the result
The result is a ceiling, not a prediction. Corners, edges and surface usually decide the grade, and PSA describes its limits as approximate and lets eye appeal count. A photo taken at an angle or a sleeve can shift the measurement by several points.
Sources and checks
Grading scales read on 27 October 2026 on each company’s website.