Find your ideal face mask size from facial measurements. Covers N95, KN95, surgical, and cloth masks with fit-check guidance.
A face mask only protects you if it fits properly. Gaps around the nose, cheeks, or chin allow unfiltered air to bypass the filtration material entirely. This face mask sizing calculator uses your facial measurements to recommend the correct mask size across N95 respirators, KN95 masks, surgical masks, and cloth face coverings.
The two critical measurements are nose-to-chin distance (face length) and ear-to-ear distance across the nose bridge (face width). These determine whether you need a small, medium, or large mask in most systems. N95 respirators require the most precise fit since they're designed to seal against the skin, while surgical and cloth masks are more forgiving.
Beyond basic sizing, the calculator provides a fit-check walkthrough — the user seal check procedure that OSHA recommends for respirators. It also covers mask types by protection level, proper wearing technique, and common fit problems with solutions. Whether you're selecting PPE for workplace safety or choosing everyday masks, accurate sizing significantly improves both comfort and protection.
An ill-fitting mask provides a false sense of security. This calculator matches your facial dimensions to the correct mask size for maximum protection and comfort, whether for workplace safety or personal health. Keep these notes focused on your operational context. Tie the context to the calculator’s intended domain. Use this clarification to avoid ambiguous interpretation.
Mask Size Index = (face length + face width) / 2. Small: index < 11.5 cm, Medium: 11.5–13 cm, Large: > 13 cm. N95 sizing follows NIOSH panel test dimensions.
Result: Medium (most N95 brands)
Size index = (12 + 13) / 2 = 12.5 cm, which falls in the Medium range. For N95 respirators, this matches 3M 8210 Medium or Honeywell DC365 Regular.
N95 respirators filter 95%+ of airborne particles and form a tight face seal — the gold standard for respiratory protection. KN95 masks offer similar filtration with ear loops instead of head straps. Surgical masks are primarily source control (protecting others from your droplets) with moderate self-protection. Cloth masks vary widely based on fabric layers and weave tightness.
A perfectly rated N95 with gaps around the nose provides less real-world protection than a well-fitted KN95. Studies show that fit accounts for 40-60% of actual protection. The filtration material only works on air that passes through it — air taking the path of least resistance through gaps bypasses the filter entirely.
Children need specially sized masks — adult masks leave large gaps. People with beards cannot get a proper N95 seal; powered air-purifying respirators (PAPRs) are the alternative. Glasses wearers should ensure the nose wire is tight enough to prevent fogging, which indicates air leakage.
For face length, measure from the bridge of your nose (between your eyes) straight down to just below your chin. For face width, measure from ear to ear across the bridge of your nose. Use a soft tape measure or string.
N95 is the US standard (NIOSH-certified) requiring ≥95% filtration with a tight face seal. KN95 is the Chinese standard (GB2626) with similar filtration but different fit-testing requirements. Both filter 95%+ of particles when properly fitted.
Put on the mask, mold the nose bridge, and cup both hands over the mask. Inhale sharply — the mask should pull inward. Exhale — you shouldn't feel air leaking around the edges. If air escapes, readjust or try a different size.
Not necessarily. Size medium in one brand may fit differently than in another due to face seal design, head strap tension, and nose bridge shape. Always do a fit check with each new brand.
Standard surgical masks are typically one-size-fits-most. Some brands offer small (child/petite) and large sizes. Proper wearing technique (pleats down, nose wire molded) matters more than size for surgical masks.
Tight enough to seal around your nose and cheeks without gaps, but not so tight it causes discomfort, headaches, or red marks. You should be able to breathe comfortably through the filter material.