I totally understand why this can feel confusing—there’s a lot of numbers and ratios thrown around, and it’s not as simple as a 1:1 increase. A lip lift works by shortening the space between the base of your nose and your upper lip (the philtrum), which in turn rotates and slightly rolls out the upper lip. The general rule that surgeons reference is that for every millimeter of skin removed from the philtrum, the upper lip typically moves 0.5 to 0.7 mm forward and curls outward, not a full 1:1. So if someone had a 4 mm lip lift, you might see roughly a 2–3 mm increase in lip projection. For an 8 mm lip lift, the increase could be somewhere around 4–5 mm, depending on your natural anatomy, lip thickness, and elasticity of your skin. It’s also important to remember that the visual change isn’t just vertical—it also subtly changes the curvature of your upper lip, making the cupid’s bow more defined and the teeth more visible when you smile. Everyone’s face reacts a little differently, so the ratios are really averages rather than guarantees. The key takeaway is that a lip lift enhances projection and shows more of your upper teeth, but the exact millimeters of forward movement depend on your unique anatomy, so small differences in lift can have a noticeable effect without being strictly linear.