Card Centering Tool

What card centering means

Centering is how evenly the printed design sits between the four edges of a card. Cards are printed many to a sheet and then cut, and the cut is almost never dead centre, so one border ends up wider than the one opposite. Graders measure the two borders on each axis and write the split as a ratio.

A card with a 3 mm left border and a 3 mm right border is 50/50. With 3 mm on the left and 2 mm on the right, the left border is 3 of the 5 mm total, so it's 60/40. The first number is always the wider border's share, and the closer it gets to 50 the better.

Every card gets four of these numbers: left to right and top to bottom on the front, and the same again on the back. Graders take the worse of the two on each side. A card that is 51/49 left to right but 62/38 top to bottom is a 62/38 card as far as the front is concerned.

How graders measure centering

Every major grading company measures from the cut edge of the card to the edge of the printed border, then compares opposite sides. On a standard Pokémon card front that means the card edge to the inside of the yellow border. On the back it's the edge to where the blue border meets the swirl.

Ace Grading measures all eight border edges under a microscope, to a thousandth of a millimetre, and uses the worst opposite pair. Their Grading Report shows the centering result on its own if you want to see what they got. Other companies don't publish their method in that much detail, but they all work from the same borders.

Back centering: why it matters more than people think

The back of a Pokémon card has a thin blue border that shifts a lot from sheet to sheet. It's common to see a gorgeous 52/48 front on a card with a 65/35 back. Most companies give the back more room than the front, but not all of them give it the same room.

Ace is the clearest example. Its Gem Mint 10 allows up to 60/40 on the front, which is a little kinder than PSA's roughly 55/45. On the back, though, Ace still wants 60/40, while PSA lets a 75/25 back through for a 10. So a card that would pass PSA's centering can come back from Ace as a 9 purely because of the reverse. Neither company is wrong; they measure the same card against different rules. That's why the tool asks for both sides.

PSA 10 centering requirements, front and back

PSA's grading standard for a Gem Mint 10 asks for approximately 55/45 or better on the front and 75/25 or better on the back. A PSA 9 allows about 60/40 on the front and 90/10 on the back, and a PSA 8 about 65/35 on the front with the same 90/10 back.

So how off-center can a PSA 10 be? On the front, not much: a 56/44 card is already outside the written standard, and on a 63 mm wide card that's a difference of well under a millimetre between the two borders. The back is far more forgiving. Until early 2025 PSA's wording allowed 55/45 to 60/40 on the front of a 10, which is why a lot of older guides and forum posts still say a 60/40 card can be a PSA 10. By the current wording it's a 9 on centering.

For a side-by-side of every grader, a worked example and why the same card can miss a 10 for different reasons, read our guide: what centering you need for a PSA 10 or an Ace 10.

Ace Grading centering requirements

Ace publishes its limits in its own blog post on how it measures centering. A Gem Mint 10 needs better than 60/40 on the front and better than 60/40 on the back. A 9 allows 65/35 on the front and 70/30 on the back, an 8 allows 70/30 and 75/25, and a 7 allows 75/25 and 80/20. Ace grades in whole numbers, so there are no half grades to aim for.

Off-center or miscut?

Off-centre means the borders are uneven but the card is still a normal card. Miscut is a different fault: you can see a sliver of the next card's border, or the edge of the printed sheet, along one side. Graders treat a miscut as its own defect and it usually sinks the grade regardless of the numbers. PSA can also add an OC (off-centre) qualifier to a card that's otherwise strong but badly centred.

Checking centering on One Piece, Lorcana, sports and other cards

The method is the same for every trading card with a printed border: measure from the cut edge to the edge of the printed frame on each side, then compare opposite sides. One Piece, Magic, Lorcana, Riftbound, Gundam and most sports cards are the same 63 × 88 mm size as Pokémon, so the tool's default setting is right for them. Yu-Gi-Oh! and Japanese small-size cards are 59 × 86 mm; pick the small size so the millimetre readings are right. The ratios themselves don't depend on the size.

Where the artwork runs right to the edge, as on many alternate art, leader and parallel cards, there may be no flat border to measure. Use the thinnest printed frame line or the nearest straight design line that runs parallel to the edge, and use the same kind of line on all four sides. The blue lines in the tool can go on any line you choose.

Ways to check card centering compared

Centering mistakes that cost people a grade

• Measuring to the artwork. The picture box is printed separately from the border and can drift in a different direction. Graders measure the border.
• Trusting your eye. A 58/42 card looks off to most people and still makes an Ace 10. A 61/39 looks the same and doesn't. Measure it.
• Skipping the back. Plenty of surprise 9s come down to back centering. Check it before you pay the fee.
• Photographing at an angle. Tilt makes the near border look wider. Shoot straight down, or scan it.
• Measuring through a sleeve. The sleeve edge becomes a fake card edge. Bare card, flat, good light.

What to do with your centering result

If a card sits comfortably inside the 10 limits front and back, centering won't be what holds it back, so it's worth looking hard at the corners, edges and surface next. If it's right on a boundary, re-measure from a fresh photo or a scan before deciding. And if the centering caps it at an 8 or 9, grading can still make sense for a card whose value holds up at that grade; it just stops being a lottery ticket for a 10.

When you're ready to send cards off, our Ace Grading discount code takes 5% off the submission. Every slab we sell in the Ace graded and PSA graded collections shows its grade and certificate number, so you can compare real centering against the numbers here.