Arm Length Measurement Calculator

The measurement of arm length is the distance from the tip of shoulder to the tip of the little finger. It is a simple though important measure in the anthropometrical profiling of athletes for certain sports. See also the similar arm span measurement, which is a measure of the total distance from one fingertip to the other.

What is Arm Length Measurement?

Arm length measurement is a fundamental anthropometric assessment used extensively in athletic testing and sports science. This measurement quantifies the distance from the acromiale (the bony prominence at the tip of the shoulder) to the tip of the little finger when the arm hangs naturally at the side of the body.

In professional sports, arm length is a critical metric that influences performance across multiple disciplines. Research by sports scientists at the University of California, Berkeley, analyzing over 10,000 athletes, demonstrates that arm length relative to height significantly correlates with success in sports like basketball and mixed martial arts. According to sports science expert Robert Wood, who has analyzed sports performance data for over 25 years, arm length measurements provide valuable insights into an athlete's physical capabilities and potential advantages in specific sports.

How to Use the Arm Length Calculator

Using the arm length calculator is straightforward and provides immediate insights into your athletic measurements:

1. Select Your Unit System: Choose between metric (centimeters) or imperial (inches) using the toggle switch at the top of the calculator
2. Enter Your Arm Length: Input your measured arm length from shoulder to fingertip in your selected unit
3. Use Quick Reference Standards: Click preset buttons for instant comparison to NFL average (33"), NFL elite offensive tackle (35"), or NBA average (34") measurements
4. Calculate Results: Click the green "Calculate Arm Length" button to receive comprehensive analysis
5. Review Your Athletic Profile: Examine your classification, percentile ranking, and sport-specific advantages
6. Compare to Standards: View how your measurement compares to NFL Combine benchmarks and other athletic standards

Pro Tip: For the most accurate measurement, ensure your fingers are fully outstretched and your arm hangs naturally at your side. Measure in the morning for consistency, as measurements can vary slightly throughout the day due to fluid distribution and muscle tension.

Understanding Your Arm Length Results

Your arm length measurement provides valuable insights into your athletic potential across various sports. The calculator classifies your measurement into four categories based on established athletic standards:

Athletic Classifications

The Science Behind Arm Length Measurement

Test Purpose: Long arms are advantageous for some sports which involve reaching and tackling.

Equipment Required: Ruler or tape measure.

Pre-test: Explain the test procedures to the subject. Perform screening of health risks and obtain informed consent. Prepare forms and record basic information such as age, height, body weight, gender, test conditions. Ensure that the subject is adequately warmed-up. See more details of pre-test procedures.

Procedure: The subject stands with the arms hanging loosely by the side of the body, fingers outstretched. A measurement is made from the acromiale (lateral edge of the acromion process, e.g. bony tip of shoulder) to the tip of the little finger. Measurement is made on the right side, following the anthropometric standard, though a measurement of either side would be assumed to be the same in most cases.

Measurement Technique

Proper measurement technique is essential for accurate results and meaningful comparison to athletic standards. The acromiale landmark is located by palpating (feeling) the outer edge of the shoulder where the clavicle meets the scapula. This bony prominence serves as the consistent starting point for all arm length measurements in sports science.

The endpoint is the tip of the little finger (also called the fifth digit or pinky finger) with fingers fully extended. Some athletic testing protocols, particularly in combat sports, measure to the middle finger tip, which typically adds 1-2 cm to the measurement. Our calculator follows the sports science standard of measuring to the little finger, as used in AFL Draft Camp testing.

Accuracy and Reliability

When performed correctly by trained personnel, arm length measurement demonstrates high reliability (±0.5 cm test-retest variation). Factors affecting measurement accuracy include:

• Finger extension: Incomplete finger stretching reduces measured length by 1-3 cm
• Shoulder position: Shoulder elevation or depression affects the starting landmark
• Body posture: Leaning or asymmetric standing alters the measurement
• Time of day: Spinal compression from daily activities may minimally affect shoulder position

Advantages: It is a very low cost, simple and quick test to perform.

Other Comments: It is important for the subject to fully stretch out the fingers to get the maximum length. This test is used at the AFL Draft Camp

Arm Length in Professional Sports

Arm length measurements play different roles across the sports spectrum, with certain positions and disciplines placing premium value on extended reach.

American Football (NFL)

The NFL Combine measures arm length as a standard part of athletic assessment, with position-specific benchmarks that influence draft decisions. According to Yahoo Sports analysis of NFL Draft prospects, offensive tackles with arm lengths below 33 inches face questions about their ability to protect the quarterback's blind side.

Basketball (NBA)

Basketball players demonstrate some of the most impressive arm measurements in professional sports. Research published in the Journal of Anthropology of Sport and Physical Education found that NBA players have an average arm span-to-height ratio of 1.063, significantly higher than the general population.

While our calculator measures single arm length, NBA scouts focus heavily on total wingspan (arm span). Elite players like LeBron James and Kevin Durant possess arm spans considerably greater than their heights, providing advantages in rebounding, shot blocking, and defensive coverage. According to sports science expert Robert Wood, these extended measurements translate directly to increased vertical and horizontal reach, allowing players to affect more of the court without repositioning.

Boxing and Mixed Martial Arts

Combat sports place enormous emphasis on reach advantage. In boxing and MMA, reach is measured as arm span (fingertip to fingertip), but arm length contributes directly to this measurement. Fighters with longer arms can strike opponents while remaining outside their opponent's range.

Notable examples include former UFC Heavyweight Champion Jon Jones, whose reach of 84.5 inches (215 cm) from a height of 76 inches (193 cm) represents an exceptional 8.5-inch advantage. Boxer Sonny Liston, despite standing only 73 inches tall, possessed an 84-inch reach. However, research indicates that while reach provides tactical advantages, it doesn't predict fight outcomes as strongly as technique and training.

Swimming

Swimmers benefit significantly from longer arms, which function as natural paddles increasing propulsion efficiency. Michael Phelps, winner of 23 Olympic gold medals, has an arm span 10 cm greater than his height. This anatomical advantage reduces the number of strokes needed per lap and improves stroke efficiency, contributing to his dominance in the sport.

Australian Rules Football

The AFL Draft Camp includes arm length measurement as part of standard athlete assessment. Players with longer arms demonstrate advantages in marking (catching), handballing at extension, and tackling at distance. The measurement helps scouts evaluate a player's physical tools relative to their position requirements.

Rock Climbing

Climbers often discuss the "ape index" (arm span relative to height), with longer arms theoretically beneficial for reaching distant holds. However, research on elite climbers shows mixed results. While many top climbers possess positive ape indices, studies have not consistently demonstrated that arm length predicts climbing performance, suggesting technique and training may override pure anatomical advantages.

How Arm Length Affects Athletic Training

Understanding your arm length has practical applications beyond sports selection, influencing training methodology and exercise prescription.

Strength Training Considerations

Arm length directly impacts biomechanics in resistance exercises, particularly the bench press. Research published in The Sport Journal examining female track and field athletes found that longer arm spans predicted decreased performance in pre-fatigued bench press conditions. Athletes with longer arms must move the barbell through a greater range of motion, increasing both the work performed and the fatigue accumulated.

Training Implications for Long Arms:

• Reduce set volumes in pressing movements to prevent excessive fatigue
• Focus on explosive power rather than maximum single-rep attempts
• Emphasize lockout strength with partial range movements
• Allow additional recovery time between upper body pressing sessions

Training Implications for Short Arms:

• Leverage mechanical advantage in bench press for higher relative loads
• Emphasize full range of motion to maximize muscle development
• Incorporate paused repetitions at chest to build starting strength
• Focus on deltoid and tricep development for arm aesthetics

Sport-Specific Training

Athletes with longer arms should emphasize different training focuses than those with shorter arms:

For Athletes with Long Arms (33"+): Develop punching power through plyometric exercises, practice maintaining effective striking distance in combat sports, train extension strength for basketball rebounding, and emphasize speed to capitalize on reach advantages before opponents can close distance.

For Athletes with Shorter Arms (Under 30"): Develop explosive closing speed to negate opponent reach advantages, train inside fighting techniques in combat sports, emphasize positioning and footwork over pure physical reach, and develop superior technique to compensate for anatomical limitations.

Frequently Asked Questions