Print size & resolution calculator
Choose your print size and resolution. This calculator shows the pixel dimensions you need and helps you spot a shape mismatch before you order a print.
Ppi means pixels per inch. The 300 ppi default is a planning value; confirm your printer’s requirement.
30 × 40 cm · 300 ppi
Your calculations stay in this browser.
Common photo and poster sizes
Reference sizes for any image. The four KeptStars download sizes are listed separately below.
| Print size | 150 ppi | 300 ppi |
|---|---|---|
| 30 × 40 cm | 1772 × 2362 | 3543 × 4724 |
| 50 × 70 cm | 2953 × 4134 | 5906 × 8268 |
| A3 · 29.7 × 42 cm | 1754 × 2480 | 3508 × 4961 |
| A2 · 42 × 59.4 cm | 2480 × 3508 | 4961 × 7016 |
| A4 · 21 × 29.7 cm | 1240 × 1754 | 2480 × 3508 |
| 8 × 10 in | 1200 × 1500 | 2400 × 3000 |
| 8.5 × 11 in | 1275 × 1650 | 2550 × 3300 |
| 11 × 14 in | 1650 × 2100 | 3300 × 4200 |
| 12 × 16 in | 1800 × 2400 | 3600 × 4800 |
| 16 × 20 in | 2400 × 3000 | 4800 × 6000 |
| 18 × 24 in | 2700 × 3600 | 5400 × 7200 |
| 24 × 36 in | 3600 × 5400 | 7200 × 10800 |
KeptStars file sizes
These are the four sizes currently offered in the designer. Landscape files swap the dimensions. Final PNG files are prepared at approximately 300 ppi; the PDF keeps the selected physical size.
| Print size | Pixels needed |
|---|---|
| 30 × 40 cm | 3543 × 4724 px |
| 50 × 70 cm | 5906 × 8268 px |
| A3 · 29.7 × 42 cm | 3508 × 4961 px |
| A2 · 42 × 59.4 cm | 4961 × 7016 px |
The PDF contains raster artwork. It is not an infinitely scalable vector file. Bleed and crop marks are not included.
How the calculation works
Convert centimetres to inches by dividing by 2.54. Multiply each side by the chosen pixels per inch, then round to the nearest pixel. For an existing image, divide its pixel dimensions by the print dimensions in inches.
At 300 ppi, 30 × 40 cm needs approximately 3543 × 4724 pixels. A 12 × 16 in print needs 3600 × 4800 pixels. The shapes match, but the sizes are not identical.
Check the shape before the frame
A 30 × 40 cm design has a 3:4 ratio. A3 is 29.7 × 42 cm, so it has a different shape. Fitting preserves the full design and leaves space; filling removes part of it. Ask the printer to preserve the complete wording and composition.
Before you print
- Use the final PDF or PNG, not a website screenshot or preview.
- Confirm the dimensions, bleed, margins and colour requirements with your printer.
- Check the print preview for cropping, spelling and scale.
- Printing and framing are separate purchases.
Questions before you buy
Does 300 ppi guarantee a good print?
No. It describes how many pixels fit in each printed inch. The source image, printer, paper and viewing distance also affect the result. Ask your print provider for its requirements.
Can I turn a small preview into a high-resolution file?
Changing the resolution label does not add the missing image detail. Use the purchased production file rather than a browser preview.
Should I send the PDF or PNG to my printer?
Use the format your printer requests. KeptStars supplies both after payment, artwork preparation and final approval. The PDF preserves the selected page size; the PNG supplies the image in pixels.
Are 30 × 40 cm and 12 × 16 inches the same?
They have the same 3:4 proportions, but different dimensions. A 12 × 16 inch print measures 30.48 × 40.64 cm.
How large can I print a 3000 × 4500 pixel image?
At 300 ppi, it measures 10 × 15 inches (25.4 × 38.1 cm). At 200 ppi, it measures 15 × 22.5 inches (38.1 × 57.15 cm). These calculations keep the whole image; they do not guarantee print quality.