iPhone Screenshots


-The Multiplier App automates calculations to predict mature height and bone length in children. This method was created originally in Baltimore at the University of Maryland, and subsequently developed at the International Center for Limb Lengthening (ICLL), Rubin Institute for Advanced Orthopedics (RIAO), Sinai Hospital of Baltimore.

-We have taught the Multiplier Method for more than 10 years at our annual Baltimore Limb Deformity Course (www.DeformityCourse.com). These calculations are typically performed by hand, using various formulas. Certain calculations are easy, but others involve more complicated formulas. Utilizing this App will reduce the time needed for these routine calculations, and decrease errors. You need only input the values about a patient (sex, age, length) and the App will execute the required Multiplier formula.

The Multiplier App will allow you to make the following calculations:
• Lower Extremity
- Limb Length Discrepancy (LLD) (Congenital)
- LLD (Developmental)
- Growth Remaining
- Bone Length
- Timing of Angular Correction
- Timing of Epiphysiodesis
- Comprehensive (Congenital) Limb Length Discrepancy and Epiphysiodesis
• Upper Extremity
- LLD (Congenital)
- LLD (Developmental)
- Growth Remaining
- Bone Length
• Height and CDC Growth Charts
- Calculates height at maturity, calculates height at every age, and plots the patient’s height and weight on the CDC growth charts
• Achondroplasia
- Height
- Sitting Height
- Leg Length
• Fetus
- Length of tibia or femur at birth and maturity
• Foot
- Foot Length
- Foot Length Discrepancy
• Spine
- Sitting Height at Maturity
•Bone Age: Elbow
- Shows a radiographic scoring system to determine skeletal age
• Bone Age: Hand
- Shows you how to use radiographic criteria to determine skeletal age
• Oblique Plane Deformity
- Calculates magnitude, orientation, and direction of an oblique plane deformity
• Inclined Osteotomy Rotation Angle
- Calculates the rotational orientation and the vertical inclination of the osteotomy

This APP also provides the following additional resources:
Figures that show the standard measurements for the lower limb and foot, the multiplier formulae that the app uses to perform the calculations, tables that show the values that are used in the multiplier formulae, figures that show the development of the apophyses, epiphyses, and bones, a bibliography, and a user guide.

Disclaimer: No growth prediction method is 100% accurate; this App is not a substitute for sound and careful clinical judgment.

What's New

Version 6.0

We changed the formatting of several results screens to make them easier to read and understand. If you decide to e-mail the results of the calculations, we have improved the content and the formatting of these e-mails. The Additional Resources section now includes the latest illustrations for the normal angles and measurements of the foot. We revised the content and improved the formatting of many of the help menus. We added a new article to the bibliography list that is located in the Additional Resources section. This 2016 article is a research study that was published in the Journal of Pediatric Orthopaedics that evaluates the use of the Multiplier App to predict growth and epiphysiodesis. The app is now optimized for iOS 10.

Ratings and Reviews

Lots of fun! Fairly consistent. Hope it's accurate!


I've had this app for several years. I have been tracking both of my daughters and the predictions have been fairly consistent throughout the years. I recently started tracking my infant son as well and I hope the predictions are correct, although I won't know for several years. I am very short and my husband is tall, so it's fun to use this for an idea of how tall my children will grow. Side note: I only use the height predictor. I have not tried the other functions.

Quick and well designed


As a pediatric orthopedist with a focus in deformity correction, I find this app to be an excellent resource. Within the limits of the data on which the program is based, I have not found a better resource. Excellent for quick teaching and calculations in the office setting.

Useful easy-to-use app

Peds ortho

Very clinically useful app - can be easily used in the middle of a busy clinic to calculate limb length discrepancy, growth remaining, timing of epiphysiodesis and much more; very helpful resources in "Additional resources" for bone age, normal joint angles and oblique plane deformity calculations. Growth charts are great to show parents. Highly recommend.


LifeBridge Health
34.1 MB
Requires iOS 7.1 or later. Compatible with iPhone, iPad, and iPod touch.
Age Rating
Rated 12+ for the following:
Infrequent/Mild Medical/Treatment Information
© Sinai Hospital of Baltimore, Inc.


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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