Method & sources

The numbers behind the print.

Simple geometry, with every assumption in view.

Uncropped print size

Use the original width and height in pixels and a target resolution in pixels per inch (PPI).

Width in inches = pixel width ÷ target PPI
Height in inches = pixel height ÷ target PPI
Centimeters = inches × 2.54

For a 6,000 × 4,000 px image at 300 PPI, the uncropped print is 20 × 13.333333 inches, or 50.8 × 33.866667 cm. This does not resample the source image.

Filling a frame

PrintBatch allows rotation and aligns the long edge of the image with the long edge of the frame. Let S and L be the source image’s short and long edges in pixels, and s and l the frame’s short and long edges in inches.

Frame PPI = min(S ÷ s, L ÷ l)
Retained fraction = (s × l × frame PPI²) ÷ (S × L)
Crop percentage = (1 − retained fraction) × 100

The image fills the frame without stretching, using a centered crop. The crop percentage measures area removed, not the percentage trimmed from each edge. No mat, border, bleed or printer margin is included. For imported photos, the preview shows the actual image with the retained frame outlined and the removed area shaded. The preview is scaled down for display; calculations use the dimensions decoded from the original file. Manual dimension rows have no image preview.

Three checks you can reproduce

“Meets target” means frame PPI is at least the chosen target. Comparisons use the unrounded value. Displayed results use up to two decimal places; the CSV uses six. If rounding would hide a below-target result, the PPI display uses a less-than sign. Floating-point noise is clamped to keep crop area between 0% and 100%.

What a PPI target can tell you

300 PPI is a common starting point for detailed prints viewed close up. Requirements depend on the output device, material and viewing distance. The 150 and 300 PPI buttons are editable presets, not a quality guarantee. This tool does not assess focus, compression, color, sharpening or the quality of upscaling.

Local photo import

Add JPEG, PNG or WebP files, up to 100 images in a batch. Each file must be no larger than 25 MB and contain at most 60 million pixels. The browser decodes dimensions, including the orientation it reads from the file. A smaller preview is made in browser memory; the original file is not modified. Unsupported, damaged, oversized and duplicate files are reported and excluded. The first successful import replaces the sample batch.

The starting sample batch uses illustrative source dimensions (6,000 × 4,000, 3,600 × 2,400 and 2,400 × 1,600) with smaller AI-generated preview images. These dimensions demonstrate the calculator and are not the sizes of the preview assets. Sample CSV names start with [Sample]. Real imports always use decoded file dimensions.

Manual dimensions and export limits

Enter one record per line: name,width,height. A matching header is optional. CSV names can include escaped double quotes and commas; tabs from spreadsheet columns are also accepted. Multiline names are not supported. Image names may have up to 200 characters, and pixel dimensions must be positive whole numbers no larger than 10,000,000. Target PPI can range from 1 to 10,000.

The first 100 nonempty data rows are processed, including invalid rows in that limit. Valid rows remain available while errors identify excluded lines. A missing or invalid PPI clears all results and disables export. CSV exports use UTF-8 with a byte-order mark, CRLF line breaks and quoted fields. Names beginning with spreadsheet formula markers are prefixed with an apostrophe to reduce formula interpretation. Spreadsheet import behavior can vary.

Sources and checks

• Adobe: print resolution for images — PPI targets and viewing distance.
• NIST Engineering Metrology Toolbox — the exact inch definition, 25.4 mm (2.54 cm).

The equations above are geometric derivations. The independent numerical cases check the implementation; they do not constitute an external print-lab review.

Method and sources checked: 6 October 2026.