Pixels to inches & centimetres
Convert a pixel measurement to its printed size in inches and centimetres at a chosen resolution — so you know how big an image will come out before you send it to print.
Result
Length
Length
How to use this tool
- Enter the pixel measurement, such as an image's width.
- Enter the print resolution (DPI/PPI) — 300 is the usual target for photo-quality prints.
- Read the printed length in inches and centimetres. Repeat with the height for the other side.
Assumptions
- Pixels only have a physical size once you fix a DPI — the same pixel count prints larger at a lower DPI and smaller at a higher DPI.
- The printer or lab prints the image at the DPI you enter, without cropping or scaling to fit.
Sources & reference data
Technical details: what the fields mean
- Pixels
pixels - The pixel dimension you're converting, e.g. an image's width from its file properties.
- Resolution
dpi - Pixels per inch at print time — 300 for photos viewed close up, 150 for posters, 72–96 is a screen convention and not a print setting.
Methodology
Inches = pixels ÷ DPI. Centimetres = inches × 2.54 (the inch is defined as exactly 25.4mm).
Worked example
1800 pixels at 300 DPI
Inputs: Pixels: 1800, Resolution: 300 DPI
Result: 6.00 in / 15.24 cm — the long side of a 6×4-inch photo print.
The same 1200px image at two resolutions
Inputs: Pixels: 1200, Resolution: 300 and thenResolution: 150 DPI
Result: 4.00 in (10.16 cm) at 300 DPI, or 8.00 in (20.32 cm) at 150 DPI. Halving the DPI doubles the size but halves the sharpness.
An A4 page designed at 300 DPI
Inputs: Pixels: 3508, Resolution: 300 DPI
Result: 11.69 in / 29.70 cm — exactly A4's 297mm long side, which is why 3508 × 2480 px is the usual A4 canvas.
Practical guidance
- Use 300 DPI for photo-quality prints viewed up close, and 150 DPI or lower for large posters viewed from a distance — see the poster-dimension helper.
- Changing the DPI field in an image editor without resampling only changes the printed size; the pixels, and the detail, stay the same.
- Working the other way — the pixels you need for a print size — is pixels = inches × DPI; the photo print-size calculator does that for common sizes.
Common mistakes
- Assuming a pixel count has a fixed physical size — it only does once you specify the DPI you're printing at.
- Reading the 72 DPI shown in a web image's metadata as its print size; screens ignore that value.
FAQs
How many inches is 1800 pixels?
At 300 DPI, 6 inches (15.24cm) — the physical size depends on the DPI you choose.
How many centimetres is 1800 pixels?
At 300 DPI, 15.24cm. At 150 DPI it would print twice as long, 30.48cm.
How many pixels is one centimetre?
At 300 DPI, about 118 pixels (300 ÷ 2.54). At 150 DPI, about 59.
Last reviewed: 2026-09-25
A direct arithmetic conversion — the DPI you should use depends on viewing distance and the quality you need.
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