3×4 Photo Size: Pixels, Inches, Uses and How to Make One Online

Quick answer: A 3×4 photo is 3cm × 4cm (30×40mm, 1.18×1.57in). In pixels, that's 354×472px at 300 DPI, or 708×945px at 600 DPI — the exact pixel count depends on the resolution your document or portal requires. It's commonly used for Portuguese, Romanian, and Mongolian visas, plus various national ID and admission forms.

A 3×4 photo measures 3 cm wide by 4 cm tall (30×40mm) — but the exact pixel count you need depends on the DPI you're printing or uploading at, which is the part most size-conversion guides skip past.

3×4 Size in Every Unit

Why the Pixel Count Isn't One Fixed Number

This is the detail most 3×4 guides gloss over: pixel dimensions change depending on the resolution (DPI) required, and different documents or printers specify different DPI values. A photo studio printing at 300 DPI needs 354×472px; a government portal requiring 600 DPI needs 708×945px for the same physical size. Uploading a 354×472px file where 600 DPI is required will look correct on screen but print or scan as lower quality than the receiving institution expects.

Before you resize an image for 3×4 use, check:

1. What physical size is required (usually 3×4cm, but confirm)
2. What DPI/resolution the receiving institution specifies
3. Calculate pixels as: (cm ÷ 2.54) × DPI for each dimension

Where a 3×4 Photo Is Required

• Portuguese visa applications
• Romanian visa applications
• Mongolian visa applications
• Various national ID cards, driving licences, and academic/admission forms (country-dependent — always confirm with the specific institution)

Requirements Beyond Just Size

A correctly sized photo can still be rejected if it doesn't also meet:

• Background: plain white, off-white, or light grey/blue depending on the country
• Recency: typically within the last 6 months
• Quality: no shadows, blur, or visible pixelation
• Expression: neutral, front-facing, eyes open, mouth closed

Smartphone vs. Professional Photography

Most guides list the specs but skip a practical question: can you actually take a compliant 3×4 photo on your phone? In most cases yes, provided you:

• Use natural, even lighting facing your face (avoid backlighting)
• Photograph against a plain wall, ideally white
• Keep the camera at eye level, not angled up or down
• Avoid using portrait/blur modes, which can distort edges during automatic cropping

The harder part isn't the photo itself — it's cropping and exporting it to the exact pixel dimensions at the correct DPI without stretching or distorting the image.

FAQ

Why do different websites give different pixel sizes for a 3×4 photo? Because pixel dimensions depend on DPI, and different sources assume different resolutions. 354×472px (300 DPI) and 708×945px (600 DPI) are both "correct" for the same 3×4cm physical size — check which DPI your specific document requires.

Is 3×4 the same as a US passport photo? No. US passport photos use a 2×2 inch (51×51mm) square format, which is a different size and shape from the rectangular 3×4cm format.

Which countries require a 3×4 photo? Most commonly Portugal, Romania, and Mongolia for visas, along with various national ID and form applications — always confirm the specific requirement with the receiving institution.

Can I take a 3×4 photo with my phone? Yes, as long as you use even lighting, a plain background, and avoid blur or portrait modes that distort automatic cropping.

Does a 3×4 photo need to be in color? Typically yes, with natural skin tone — confirm with the specific document's requirements, as this can vary.

Getting the Exact Size Without the Math

Rather than calculating pixel-per-DPI conversions by hand, photoomni lets you enter the country or institution you're submitting to, and it automatically outputs your photo at the correct 3×4 pixel size and DPI for that specific use case — so you're not left guessing whether 354×472 or 708×945 is the one you actually need.