Card centering calculator

What card centering is

A card is centered when the artwork sits exactly in the middle of the cardboard, that is when the left border is as wide as the right one and the top border as wide as the bottom one. At the factory the sheets are printed and then cut, and if the cut lands slightly off, every card on that sheet comes out with one border wider and one narrower.

Centering is written as two numbers that add up to one hundred: 50/50 is the perfect card, 60/40 means that of two opposite borders one takes 60% of the space and the other 40%. There are two ratios, one between left and right and one between top and bottom, and the worse of the two is the one that counts for the grade. The math is simple: if the left border measures 3.3 millimeters and the right one 2.7, the sum is 6, and 3.3 divided by 6 is 0.55, so 55/45.

Both the front and the back are measured, and grading companies are far stricter with the front: a card can have a visibly shifted back and still get the top grade.

The PSA, Beckett and CGC thresholds

Each company publishes the centering it requires for every grade, and the tool compares your measurement with those tables, read on the official pages on November 11, 2026. PSA asks for approximately 55/45 or better on the front and 75/25 on the back for a 10; for a 9, 60/40 and 90/10 are enough, for an 8 65/35 and for a 7 70/30, always with the back at 90/10. PSA adds that, at the grader's discretion, a small variance may occasionally be allowed when the card's overall eye appeal is strong.

Beckett (BGS) is the strictest. For a 10 it wants the front at 50/50 on both axes and the back at 60/40 or better; for a 9.5, one axis at 50/50 and the other at 55/45; for a 9, 55/45 on both and 70/30 on the back; for an 8, 60/40 and 80/20. Below 9.5 Beckett also awards half grades, such as 8.5, to cards that fall between two levels.

CGC has two 10s. Pristine 10 wants 50/50; Gem Mint 10 approximately 55/45 on the front and 75/25 on the back. From 9 down, CGC writes its thresholds for sports and non-sports cards: 60/40 on the front and 90/10 on the back for a 9, 65/35 for an 8, 70/30 for a 7. The full tables of the three companies are below the tool, and after the measurement the row your card reaches stays highlighted.

How to take the photo

The measurement is only as good as the photo. What matters most is the background: lay the card on a surface of a single color that stands out from its border, dark for a card with a light border and light for one with a black border. The tool recognizes the card precisely from where the background ends, and on a table the same color as the border it has nothing to hold on to.

Hold the phone above the card, as parallel as you can, and not too close: an inch or two away the lens bends straight lines, and a curved line can't be measured. It's better to stay 12 to 16 inches away (30 to 40 cm) and use the 2x zoom. If the photo comes out a bit crooked or at an angle it doesn't matter, because the card is straightened before it is measured. A flatbed scanner, if you have one, gives the best measurement of all.

Take the card out of its sleeve, if you can do it safely. Sleeves and rigid holders have their own edges and reflections, and the tool can mistake the edge of the plastic for the edge of the card. If the card stays in the plastic, check that the four corners found are those of the card and not those of the holder.

How the tool works

The work is done in three steps. First the page looks for the card in the photo and finds its four sides, one by one, as straight lines: a card's corners are rounded, so the true corner is the point where the lines of two sides meet, which doesn't exist on the cardboard. Then the card is straightened, as if it had been photographed perfectly from above, with the same math used by Straighten a document.

On the straightened card the tool looks for the frame. For each side it starts from the outer edge and moves inward until it finds the first straight line that runs along almost the whole side: that is where the border ends and the artwork begins. A caption or a detail of the illustration doesn't fool it, because they only cover part of the side.

In the end there are eight lines, four pink ones on the edge of the card and four blue ones on the frame, and the numbers are calculated from the distances between them. Every line can be dragged, and while you move it a magnifier shows that spot enlarged; with the arrows you move it one pixel at a time. Ratios are rounded to the whole point, the way the companies write them: 55.4 is a 55/45, 55.6 is a 56/44.

When the measurement misleads

From a photo, a one-point error is normal: a line one pixel off is enough. That's why, when your card is one point from a threshold, the tool warns you that you are on the line. In that case look closely at the lines with the magnifier, and remember that the person grading the card has some leeway too: a card just over 55/45 may pass one time and not the next.

Some cards have no frame to measure. Full-art cards carry the artwork right to the edge, and there the tool tells you it couldn't find the frame: the blue lines have to be placed by hand on a reference you choose, for example the text box. Other cards have borders that differ by design: on many Magic cards the bottom border is taller than the others, because it holds the line with the print details, and there you won't get a 50/50 between top and bottom even on a perfect card.

And centering is only part of the grade. Corners, edges and surface weigh just as much, and a 50/50 card with a damaged corner won't get the top grade. This tool answers a single question, namely how far centering lets you go; the rest has to be judged by eye, under good light.

The photo stays on your phone

All the work is done by your browser: the photo isn't uploaded to any server and nobody sees it. There's nothing to install and no account is needed. It opens JPG, PNG, WebP and iPhone HEIC photos too.

You can download an image of the straightened card, with the lines and the two ratios written underneath, handy to send to someone who asks about the centering before buying. And if the card is already in a graded slab and you want to post a photo of it without showing the certification number, there's Hide the cert number on graded cards.