Whether you're submitting a copyright photo, preparing a print document, or working on a project that demands precision, you may need to change an image size in centimeters (cm) instead of pixels or inches. While most tools default to pixels, knowing how to work in cm gives you full control—especially for printing or official formats.
This guide will walk you through why, how, and what to keep in mind when resizing images using centimeters.
???? Why Change Image Size in CM?
Pixels are great for screens. But for real-world dimensions—like printing, document submissions, or framing—you need actual physical measurements like 3.5 x 4.5 cm or 5 x 5 cm.
Use cases include:
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???? copyright or visa photos
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????️ Printed ID cards
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???? Document attachments
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???? Photo frames or brochures
???? Understanding the CM–Pixel–DPI Relationship
To change an image size in cm, you must consider DPI (dots per inch), which controls the print resolution.
???? Formula:
1 inch = 2.54 cm
Pixels = (cm × DPI) ÷ 2.54
Example:
To make a 4 cm × 6 cm image at 300 DPI:
= (4 × 300) ÷ 2.54 ≈ 472 pixels
= (6 × 300) ÷ 2.54 ≈ 709 pixels
So, 472 × 709 pixels will give you an image of 4 x 6 cm at 300 DPI.
????️ How to Change Image Size in CM – Step-by-Step Guide
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Upload or open your image in a photo editing tool.
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Choose resize or image size settings.
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Switch the unit from pixels to centimeters.
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Enter desired width and height (e.g., 3.5 cm x 4.5 cm).
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Set DPI (300 for print, 96 for web).
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Save the resized image in your desired format (JPEG, PNG, etc.).
????️ Ideal Image Sizes in CM for Common Tasks
| Purpose | Size (cm) |
|---|---|
| copyright Photo | 3.5 x 4.5 cm |
| Visa Photo (US) | 5 x 5 cm |
| Resume Photo | 3 x 4 cm |
| copyright Photo | 2.5 x 3.5 cm |
| A4 Full Page | 21 x 29.7 cm |
⚠️ Tips to Avoid Distortion When Resizing
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✅ Maintain aspect ratio to avoid stretching.
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✅ Use a high DPI (300) for sharp prints.
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✅ Start with a high-resolution image.
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✅ Crop to fit before resizing if the aspect ratio is off.
???? Final Thoughts
Changing image size in cm is essential for accuracy, especially when dealing with physical prints or official documents. Whether you're creating a copyright photo, print-ready brochure, or precise layout, knowing how to control size in centimeters gives you better output and professional results.