MM to PX Converter — Pixel-Perfect, Instant, Free

1. 1

   Choose a direction

   Pick MM → PX or PX → MM at the top of the studio.

2. 2

   Enter your value

   Type any millimeter or pixel number. The result updates as you type.

3. 3

   Pick a DPI

   Use 96 for screens and CSS, 300 for print, or type a custom value.

4. 4

   Choose rounding

   Full precision, 4 decimals, 2 decimals, or whole numbers — depending on what your target needs.

5. 5

   Copy or batch

   Grab the result with one click. Need many values? Paste them into the batch box, separated by lines or commas, or upload a CSV.

Photo and document requirements differ by country and printer. Check the issuer's or printer's current specification before submitting.

• CSS
  For print stylesheets the mm unit works well and maps reliably to physical output.
• WEB
  For on-screen layouts stick with px, rem or percentages. Physical units on screens are not dependable.

/* Physical size — reliable in print, approximate on screen */
.card {
  width: 85.6mm;   /* standard credit card width */
  height: 54mm;
  border-radius: 3.18mm;
}

/* Screen layout — use px or rem instead */
.card--screen {
  width: 324px;    /* 85.6 mm at 96 DPI */
  height: 204px;   /* 54 mm at 96 DPI */
}

/**
 * Convert millimeters to pixels at a given DPI.
 * @param {number} mm  - millimeters
 * @param {number} dpi - dots per inch (default 96 for screens)
 * @returns {number} pixels
 */
function mmToPx(mm, dpi = 96) {
  return (mm * dpi) / 25.4;
}

/**
 * Convert pixels to millimeters at a given DPI.
 * @param {number} px  - pixels
 * @param {number} dpi - dots per inch (default 96)
 * @returns {number} millimeters
 */
function pxToMm(px, dpi = 96) {
  return (px * 25.4) / dpi;
}

// Example usage
console.log(mmToPx(20, 300));  // 236.2204724409449
console.log(pxToMm(200, 96));   // 52.916666666666664

• Converts both directions — mm to px and px to mm.
• DPI presets (72, 96, 150, 300, 600) or any custom value.
• Rounding choices: full precision, 4 decimals, 2 decimals or whole numbers.
• Batch conversion by pasting values or uploading a CSV, with CSV download.
• One-click copy and keyboard shortcuts.
• Works on mobile and desktop.
• Live proportional preview that shows the physical scale at a glance.
• AI tools: DPI suggestions, plain-English explanations, print checks and object matching.