Image & Resolution
Image DPI Calculator
Calculate the DPI of your image from its pixel dimensions and intended print size — or work backwards to find how many pixels you need for a target DPI. Essential for getting crisp prints every time.
Last updated: June 2026
Formula used
Required pixels = DPI × Print width (inches)
When the print width is in mm or cm, the calculator converts to inches first (1 inch = 25.4 mm). Both horizontal and vertical DPI are computed; they should match for square-pixel images.
DPI vs PPI: Technically DPI refers to printer ink dots and PPI refers to digital pixel density. In everyday print use they are interchangeable.
Example calculations
Example 1 — 3000 × 2000 px photo printed at 10 × 6.67 inches:
DPI = 3000 ÷ 10 = 300 DPI — photo quality.
Example 2 — Pixels needed for 12 × 8 inch print at 300 DPI:
Width = 300 × 12 = 3,600 px. Height = 300 × 8 = 2,400 px.
Example 3 — A4 coloring page at 150 DPI:
A4 = 8.27 × 11.69 in. Width = 150 × 8.27 = 1,241 px. Height = 150 × 11.69 = 1,754 px.
How to use this calculator
- Select mode: Calculate DPI or Find pixels needed.
- Enter pixel dimensions (width × height) of your image.
- Enter the desired print size and select the unit (in / cm / mm).
- Read the resulting DPI or pixel requirements.
DPI quality reference
| DPI | Quality level | Best for |
|---|---|---|
| 72–96 | Screen only | Web, email |
| 150 | Draft print | Coloring pages, internal docs |
| 200–240 | Good print | Brochures, school projects |
| 300 | Photo quality ✓ | Photos, professional prints |
| 600+ | Fine detail | Fine art, small text |
Notes & limitations
This calculator assumes square pixels. AI upscaling can increase pixel count but may not genuinely improve printable quality. For ColoringBuds coloring pages, 150–200 DPI is sufficient for crisp line art on A4 or Letter.
Frequently asked questions
What DPI is good for printing photos?
300 DPI is the standard for photo-quality prints. For large prints viewed from a distance (posters) 150 DPI is often acceptable.
How do I check the DPI of an image?
On Windows right-click the file → Properties → Details and look for Horizontal/Vertical resolution. On Mac open the image in Preview → Tools → Adjust Size. Or use this DPI calculator by entering the pixel dimensions and the print size.
Can I increase DPI without losing quality?
Simply changing the DPI metadata does not add detail — it only changes how the printer interprets the image size. AI upscaling tools can recover some sharpness, but there are limits.
What is a good DPI for coloring pages?
150–200 DPI gives sharp, clean lines for printed coloring pages. 300 DPI is ideal for pages with very fine details or small text.
Is 72 DPI good for printing?
72 DPI is designed for screen display and will look blurry when printed. For any print use 150 DPI minimum, and 300 DPI for photos.
What is the difference between DPI and resolution?
Resolution refers to the total pixel count (e.g. 3000 × 2000 px), while DPI is relative — it describes how many dots fit in one inch at a specific print size. A 3000-pixel-wide image at 10 inches = 300 DPI; at 20 inches = 150 DPI.