Calculate credit card dimensions in mm, cm, inches, and pixels, check a measured card against ISO/IEC 7810 ID-1 tolerance limits, and scale artwork to card size.
Credit Card Size Formula
A credit card is a rounded rectangle defined by ISO/IEC 7810 as the ID-1 format: 85.60 mm wide, 53.98 mm high, and 0.76 mm thick. Every output in the calculator comes from that rectangle and the unit or scaling operation you choose.
- A = face area of the card treated as a plain rectangle
- Ar = face area corrected for the four rounded corners
- P = perimeter of the card
- D = corner to corner diagonal
- AR = aspect ratio, width divided by height
- W = card width (85.60 mm for ID-1)
- H = card height (53.98 mm for ID-1)
- r = corner radius, typically 3.18 mm
Unit conversion uses the exact definition of the inch, so every length output is a single division or multiplication:
- in = length in inches
- mm = length in millimeters
- px = pixel count for a print or screen file
- DPI = dots per inch of the output device, 300 for print and 72 for screen
Scaling mode reduces or enlarges an image or object until it sits on the card face. Fit uses the smaller of the two ratios so nothing is cropped, and fill uses the larger so the card face is fully covered:
- S = scale factor applied to the artwork, reported as a percentage
- Wa = original artwork or object width
- Ha = original artwork or object height
Stack mode treats cards as flat sheets of uniform thickness, which is how wallet slots and card feeders are specified:
- Tstack = total height of a stack of cards
- N = number of cards
- t = thickness of one card, 0.76 mm nominal
- Sslot = depth of the slot, wallet pocket, or reader opening
- Nfit = whole number of cards that fit in that opening
The four modes of the calculator map directly onto these groups. Dimensions mode reports A, Ar, P, D, AR and the pixel sizes. Check mode compares your measured W, H, and t against the published ISO limits instead of the nominal values. Scale mode returns S along with the leftover margin or the cropped overflow. Stack mode returns Tstack or Nfit.
Card Format Sizes and ISO Tolerance Limits
The first table lists the ISO/IEC 7810 formats the calculator supports, plus CR-79, the slightly smaller adhesive card used as a label on top of a CR-80 card. Pixel values are the trim size at 300 DPI, before bleed.
| Format | Size (mm) | Size (in) | Pixels at 300 DPI | Diagonal (mm) | Typical use |
|---|---|---|---|---|---|
| ID-1 (CR-80) | 85.60 x 53.98 | 3.370 x 2.125 | 1011 x 638 | 101.20 | Credit, debit, ID, driver license |
| CR-79 | 83.90 x 51.00 | 3.303 x 2.008 | 991 x 602 | 98.18 | Adhesive overlay on a CR-80 card |
| ID-2 | 105 x 74 | 4.134 x 2.913 | 1240 x 874 | 128.46 | Visas, older national ID cards |
| ID-3 | 125 x 88 | 4.921 x 3.465 | 1476 x 1039 | 152.87 | Passport pages |
| ID-000 | 25 x 15 | 0.984 x 0.591 | 295 x 177 | 29.15 | Mini-SIM punched from an ID-1 card |
Every format above uses the same 0.76 mm nominal thickness. The second table is the part most size charts leave out: ISO/IEC 7810 does not require an ID-1 card to measure exactly 85.60 x 53.98 mm. It publishes a permitted range, and that range widens once a card has been embossed, laser engraved, or fitted with a chip. Check mode uses these numbers rather than the nominal values, so a card can read as in spec even when it is not exactly 85.60 mm wide.
| Dimension | Nominal | Limits, unused card | Limits, after personalization | Total spread |
|---|---|---|---|---|
| Width | 85.60 mm | 85.47 to 85.72 mm | 85.37 to 85.90 mm | 0.25 mm new, 0.53 mm used |
| Height | 53.98 mm | 53.92 to 54.03 mm | 53.82 to 54.18 mm | 0.11 mm new, 0.36 mm used |
| Thickness | 0.76 mm | 0.68 to 0.84 mm | 0.68 to 0.84 mm | 0.16 mm |
| Corner radius | 3.18 mm | 2.88 to 3.48 mm | 2.88 to 3.48 mm | 0.60 mm |
Two practical consequences follow from the thickness range. A wallet slot or card feeder sized on the 0.76 mm nominal will hold fewer cards than expected if the cards sit at the 0.84 mm end, and metal cards commonly run 1.2 to 1.6 mm, which is outside the standard entirely. Stack mode reports all three cases so you can size a slot for the worst one rather than the average.
Example Problems
Example 1: fitting a photo on a card. You want a 6 x 4 inch photo printed on the face of an ID-1 card with nothing cropped. Convert the photo to millimeters: 6 x 25.4 = 152.4 mm and 4 x 25.4 = 101.6 mm. The two ratios are 85.60 / 152.4 = 0.5617 and 53.98 / 101.6 = 0.5313. Fit mode takes the smaller value, so S = 0.5313, or 53.13 percent. The scaled photo becomes 152.4 x 0.5313 = 80.97 mm wide and 101.6 x 0.5313 = 53.98 mm high. The height fills the card exactly and the width leaves (85.60 - 80.97) / 2 = 2.32 mm of blank card on each side. Printing that 80.97 mm width at 300 DPI needs 80.97 / 25.4 x 300 = 956 pixels.
Example 2: checking a used card. You measure a card at 85.88 mm wide, 54.10 mm high, and 0.80 mm thick. Against the unused ID-1 limits, the width fails (85.88 is above 85.72) and the height fails (54.10 is above 54.03), so the card would be rejected at manufacture. Against the post-personalization limits, 85.88 sits inside 85.37 to 85.90 and 54.10 sits inside 53.82 to 54.18, so the card is still conforming. Thickness of 0.80 mm is inside 0.68 to 0.84 mm in both cases. The card is legitimate and should still read; the extra 0.28 mm of width is normal growth from embossing and daily flexing.
FAQ
What is the exact size of a credit card? A credit card is 85.60 mm by 53.98 mm with a thickness of 0.76 mm, which is 3.370 by 2.125 inches and 0.030 inches thick. Corners are rounded at a radius of about 3.18 mm, permitted anywhere in the 2.88 to 3.48 mm range. The face area is 4620.69 square millimeters as a plain rectangle, or 4612.01 square millimeters once the rounded corners are subtracted, and the diagonal is 101.20 mm. The original design was drawn in imperial units, which is why the inch figures are the clean ones and the millimeter figures carry decimals.
What canvas size should I use to design a credit card? Set the document to 85.60 x 53.98 mm, which is 1011 x 638 pixels at 300 DPI. Add 2 mm of bleed on every side for a full bleed print, giving 89.60 x 57.98 mm or 1058 x 685 pixels, and keep text and logos at least 3 mm inside the trim line so nothing is lost to cutting tolerance. At 600 DPI the trim size is 2022 x 1275 pixels. Never design at 72 DPI and upscale; the trim size at 72 DPI is only 243 x 153 pixels, which will print visibly soft.
Why does my card not measure exactly 85.60 mm? The standard specifies a range, not a single value, and cards drift within that range over their life. A new card is allowed to leave the factory anywhere between 85.47 and 85.72 mm wide. After embossing, chip implantation, and months of flexing in a wallet, the permitted width widens to 85.37 to 85.90 mm. Plastic also expands slightly with heat and humidity. If a card measures outside those bands, check your measuring tool first, since a plastic ruler cannot resolve tenths of a millimeter and calipers can.