Enter the interpupillary distance (in) and the distance from the pupil center to the top of the lip (in) into the Midface Ratio Calculator. The calculator will evaluate and display the Midface Ratio. 

Midface Ratio Formula

The following formula is used to calculate the Midface Ratio.

MFAC = ID / DL
  • Where MFAC is the Midface Ratio
  • ID is the interpupillary distance (in) 
  • DL is the distance from the pupil center to the top of the lip (in) 

To calculate a midface ratio, divide the interpupillary distance by the distance from the pupil center to the top of the lip.

How to Calculate Midface Ratio?

The following example problems outline how to calculate Midface Ratio.

Example Problem #1:

  1. First, determine the interpupillary distance (in).
    • The interpupillary distance (in) is given as: 4.5.
  2. Next, determine the distance from the pupil center to the top of the lip (in).
    • The distance from the pupil center to the top of the lip (in) is provided as: 5.
  3. Finally, calculate the Midface Ratio using the equation above: 

MFAC = ID / DL

The values given above are inserted into the equation below and the solution is calculated:

MFAC = 4.5 / 5 = .9

Example Problem #2: 

For this problem, the variables required are provided below:

interpupillary distance (in) = 3.5

distance from the pupil center to the top of the lip (in) = 4

Test your knowledge using the equation and check your answer with the calculator above.

MFAC = ID / DL = ?