Free AI head-size checker for passport photos. Measures the chin-to-crown height against your country's official requirement. Works for 166 countries.
Head-Size Rules by Country
Different countries enforce different head-size ratios. Below: the official spec for the 10 most common passport photo destinations.
| Country / document | Head-size requirement |
|---|---|
| United States (passport, visa, green card) | 50–69% of frame height (1 to 1 3/8 inches from chin to crown) |
| United Kingdom (passport) | 29–34 mm from chin to crown (within 35×45mm frame) |
| Schengen / EU (most countries) | 32–36 mm from chin to crown |
| India (Passport Seva) | 70–80% of frame height (full face fills the frame) |
| China (visa) | 32 mm minimum from chin to crown; ears must be visible |
| Canada (passport) | 31–36 mm from chin to crown |
| Japan (passport) | 32–36 mm from chin to crown |
| Japan (residence card 在留カード) | Exactly 27 mm from chin to crown |
| Australia (passport / visa) | 32–36 mm from chin to crown |
| Saudi Arabia (eVisa) | ~70% of frame height |
How to Measure Head Size in Your Photo
- Open your photo in any image viewer that shows pixel dimensions (Preview on Mac, Photos on Windows, the iOS Photos app under the info icon).
- Identify the top of the crown (not the top of the hair if you have tall hair) and the bottom of the chin.
- Measure the pixel distance between those two points (a ruler overlay tool helps).
- Divide that by the total photo height in pixels. Multiply by 100 to get the percentage.
- Compare to your country's requirement above.
Or just upload your photo to Snap2Pass — our AI does this measurement automatically and reports the head-size ratio in 60 seconds.
Why Head Size Matters
Passport photos serve as biometric reference images. The head-to-frame ratio is calibrated for facial-recognition algorithms used at border crossings. A head outside the spec range degrades the algorithm's accuracy — which is why agencies reject non-compliant photos.
For US passports, the State Department's online validator explicitly rejects photos where the head is <50% or >69% of frame height. Industry data shows "head size out of range" in the top 5 rejection reasons (behind glasses, background tint, shadows, and AI editing).
Skip the math. Upload and check.
Our AI measures head-size, eye position, expression, background, and 20+ other compliance points. Free to check. $9.95 to download.
Check my photo →