Short answer: Card centering is how evenly a card's image sits within its borders, measured as a percentage like 60/40, and it is one of the biggest factors in a card's grade. For a PSA Gem Mint 10, you now need 55/45 or better on the front and 75/25 on the back, after PSA tightened its standard in early 2025. Centering is the single most common reason a card falls short of a top grade. Here is how to measure it and what each grading company requires.
Why centering matters so much
Of the four things graders judge, centering, corners, edges, and surface, centering is the one collectors most often overlook and the one that most often caps a grade. A card can have flawless corners, clean edges, and a perfect surface, and still be held to a 9 or lower purely because the image sits off center within the borders.
The reason is eye appeal. A well centered card looks clean and balanced, which makes it more attractive to collectors and worth more. Grading companies have measured centering as part of the grade since the practice of slabbing cards began in the 1980s, and it has been a core factor ever since.
How card centering is measured
Centering is expressed as a percentage split between opposite borders. If the left and right borders are exactly equal, the card is 50/50, perfectly centered. If one side is thicker, the split shifts, for example 60/40.
Here is the actual method. Measure the width of the two opposite borders, add them for the total, then divide each into that total. Say the left border is 3mm and the right border is 2mm. The total left to right border is 5mm. The left side is 3 divided by 5, which is 60 percent, and the right is 2 divided by 5, which is 40 percent. That card is 60/40 left to right.
Centering is measured in four places: the front left to right, the front top to bottom, and the same two on the back. Importantly, most grading companies use the worse of your two front measurements as the front centering score. So if your card is 60/40 left to right but 50/50 top to bottom, it is graded as 60/40 on the front, the lower of the two.
What centering you need for each grade
Centering requirements vary by company and by grade. The front is weighted more heavily than the back across the board. Here is where the major companies stand.
PSA was the most lenient for years, but tightened its standard in early 2025. A Gem Mint 10 now requires 55/45 front centering and 75/25 back, where it previously allowed 60/40 on the front. Moving down the scale, a PSA 9 allows roughly 60/40 front, a PSA 8 around 65/35, and a PSA 7 around 70/30.
BGS is the strictest on centering. A true 10 requires 50/50 on both the front and back, though it is worth noting BGS treats 9.5 as its Gem Mint grade, so a straight 10 is considered above and beyond. A BGS 9 needs about 55/45 front, an 8 around 60/40.
SGC sits in the middle and is notably strict on backs, requiring 55/45 on both the front and back for its top grade.
Edge Grading requires 55/45 on the front but is loose on the back at 70/30 for a 10.
The practical takeaway: if you are chasing a 10, aim for a card that looks close to 50/50 to the naked eye, and remember the back counts too, especially at SGC and BGS.
How to check centering before you grade
Because centering can cap an otherwise perfect card, checking it before you pay to grade is one of the smartest things you can do. You can measure it by hand with the method above, using a ruler on a scan, or use a centering tool or app that measures it from a photo automatically.
This ties directly into deciding whether a card is worth submitting at all. With professional grading now costing around 80 dollars per card at the cheapest widely open tier, you do not want to pay to grade a card that is visibly off center and destined for a 7. A pre grade check, including centering, tells you whether a card is a genuine 9 or 10 candidate first. An app like Cards AI reads centering along with corners, edges, and surface and estimates a grade before you submit. Our guides to the baseball card grading system and the best card grading apps go deeper, and our comparison of the grading companies covers how their standards differ.
Frequently asked questions
What centering do you need for a PSA 10? As of PSA's early 2025 standard, a Gem Mint 10 requires 55/45 or better centering on the front and 75/25 on the back. This is stricter than the previous standard, which allowed 60/40 on the front. Both front and back must meet the requirement.
How do you measure card centering? Measure the two opposite borders, add them for the total, and divide each into that total. If the left border is 3mm and the right is 2mm, the total is 5mm, so the card is 60/40 left to right. Measure front and back, and companies use the worse of your two front measurements as the front score.
What is perfect centering? 50/50, meaning the borders on opposite sides are exactly equal and the image sits perfectly centered. BGS requires 50/50 on both front and back for a true 10, the strictest standard among the major companies.
Does the back of the card count for centering? Yes. Centering is measured on both the front and back, though the front is weighted more heavily. SGC and BGS are notably strict on backs, while PSA and Edge are more lenient there. A poorly centered back can still pull down a grade.
Why is centering so important for grading? Because it is often the factor that caps a grade. A card with perfect corners, edges, and surface can still be limited to a 9 or lower by off center borders. Centering drives eye appeal, which drives value, so it is one of the first things to check before grading.
