PRACTICAL GUIDES · Images and photos
DPI vs PPI: choosing a print resolution
Connect pixel count, physical size and viewing distance. Check a ten-inch print with a worked 300 PPI example.
By Puffinmint · Updated
Separate image PPI from printer DPI
For a printed photo, the relevant density is the pixel count spread across its physical size. PPI describes that density; printer DPI describes the dots produced by the printing mechanism. They are related to output quality but describe different quantities.
Calculate from pixels or print width
Start with the image’s actual pixel dimensions, then choose a print width and unit. If a lab specifies a density, calculate the achievable print size. If you already know the width, calculate the effective PPI instead.
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Input
3000 × 2000 px; 300 PPI
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Calculation steps
Choose and apply the method
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Result
25.4 × 16.9333333333 cm
TRY THIS STEP
DPI calculator and print dimensions
Work inside this guide: load an example, run the tool and edit the inputs to compare results. The second experiment tests a different case.
A reproducible example
A 3000-pixel-wide image at 300 PPI measures ten inches, or 25.4 cm. Printing the same pixels across twenty inches reduces the density to 150 PPI. The image has not gained additional detail.
Double the print width
The second example keeps 3000 × 2000 pixels and sets a width of 50.8 cm. Calculate: density drops to 150 PPI. Change the width back to 25.4 cm and confirm 300 PPI.
Result
Enter your values to see the result.
3000 pixels at 300 PPI: 25.4 cm
A 3000-pixel-wide image at 300 PPI measures ten inches, or 25.4 cm. Printing the same pixels across twenty inches reduces the density to 150 PPI. The image has not gained additional detail.
Usage scenario
- Input
- 3000 × 2000 px; 300 PPI
- Result
Calculation steps
Convert pixels to inches
Convert the width to centimetres
Calculate the height in centimetres
Check lab requirements and real detail
Ask the printer about resolution, bleed and color-profile requirements. Suitable density also depends on viewing distance and the subject. Changing DPI metadata adds no pixels; resampling interpolates information rather than recovering original detail.
These are example inputs, rather than measurements of a real case. Results use the full tool’s calculation engine. Compare them with the worked steps in this guide, then tick the checks after reviewing.
| Parameter | Value |
|---|---|
| What are the limits of this tool? | Up to 1,000,000 pixels per side; entered density from 1 to 100,000 PPI. Images are not resampled. |
| Processing and privacy | Inputs and results are processed in your browser and are not sent to the server. Aggregate statistics, when enabled, record only the tool and outcome, without the content. |