Print Size Calculator
Convert between pixels (px), physical dimensions (mm/cm/inch), and DPI bidirectionally. Includes presets for A4, Letter, photo L-size, business cards, and recommended resolutions from 72 to 1200 dpi.
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How to Use
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- 1
Choose a paper size
Pick a preset like A4, Letter, or photo L-size, or enter physical dimensions directly.
- 2
Set the DPI (resolution)
Use 72/96 for web, 300 for print, 600+ for high-quality print. Quick chips are also available.
- 3
Check and copy the result
The required pixel count is shown instantly. Copy the full summary, pixel values, or physical size separately.
Paper preset
Pixel size
Aspect ratio: 620:877 ≈ 1:1.414
Physical size
DPI (PPI)
Result summary
- Megapixels
- 8.7 MP
- Aspect ratio
- 620:877 ≈ 1:1.414
Quick reference (pixels required per DPI)
| DPI | Pixels required | Actions |
|---|---|---|
| 72 | 595 × 842 | |
| 96 | 794 × 1,123 | |
| 150 | 1,240 × 1,754 | |
| 300 | 2,480 × 3,508Current setting | |
| 600 | 4,961 × 7,016 | |
| 1200 | 9,921 × 14,031 |
About Print Size Calculator
Print Size Calculator converts image pixels, physical dimensions, and DPI (PPI) in both directions. Choose presets such as A4, Letter, photo L-size, business cards, or postcards to see the required pixel dimensions immediately. All calculations run locally in your browser and your input is never sent to a server.
Key Features
- Bidirectional conversion between px and mm/cm/inch
- 36 presets including A/B series, US sizes, photo L-size, business cards
- One-click switching between 72-1200 dpi recommended resolutions
- Aspect ratio lock to maintain proportions
- Quick reference table showing pixel counts for 6 major DPIs
Use Cases
- Calculating required pixels for print
- Sizing images for the web (72/96 dpi)
- Verifying sizes for photo prints, business cards, postcards
- Reverse-calculating physical size (mm) from pixel count
Frequently Asked Questions
How many pixels do I need to print A4 at 300dpi?
A4 is 210×297mm; at 300dpi you need 2480×3508 pixels (rounded).
What is the difference between DPI and PPI?
DPI (Dots Per Inch) refers to print resolution, PPI (Pixels Per Inch) to digital images, but they are used interchangeably here.
What is aspect ratio lock?
When you change width or height, the other side automatically updates to maintain the ratio. The ratio is refreshed when you pick a preset.
What is the basis of the calculation?
We use 1 inch = 25.4 mm and compute px = mm × dpi / 25.4. Pixel values are rounded to the nearest integer.