Speed Calculator for Video Analysis

Understanding Speed Calculation from Video

There are many biomechanical measurements that can be made using video analysis. Described here is a comprehensive method for measuring speed of an athlete or object that anyone with a basic camera can use. This calculator supports both direct distance-time calculations and frame-by-frame video analysis. There are also several Video Analysis products that can do this and much more.

Make note of the video technique guidelines before collecting video footage for analysis. For accurate speed measurements, you will need to have video footage from directly side-on, a calibration mark that can be viewed on the screen (for distance measurement), and you need to know the frame rate of the video (or have a time scale in view).

How to Calculate Speed from Video Footage

The speed of an object is a measure of how far it moves in a set time period (measured in the units meters or feet per second, km or miles per hour etc.). Therefore the first step in calculating speed of an object on screen, is to calculate the distance the object moved. Once this is determined, you will need to know what the frame rate of the video recording is.

Frame rates can vary, often 24 or 25 frames per second for standard video, sometimes 30 frames/sec for NTSC format. For high-speed filming (slow-mo) it can be 120, 240, or even 1000 frames/sec. Modern smartphones typically record at 30 or 60 fps, with slow-motion modes offering 120-240 fps.

If your video runs at 25 frames per second, this means that there is 0.04 seconds between each frame. When you view the video frame by frame, and calculate the distance an object moves from one frame to the next, you can calculate the speed of that object. For example, if a sprinter's foot moves 50 centimeters between frames at 25 fps, this equates to a speed of 12.5 meters per second or 45 km/h.

Sport-Specific Speed Applications

Track and Field

Sprint analysis focuses on different phases of acceleration. The acceleration phase (0-30m) shows speeds increasing from 0 to about 8-9 m/s for trained athletes. Maximum velocity phase (30-60m) reaches 10-12 m/s for elite sprinters. The world's fastest recorded human speed was Usain Bolt at 12.42 m/s (44.72 km/h) during his 100m world record.

For field events, release speeds are crucial. Shot put release speeds range from 12-14 m/s at elite level, while javelin releases can exceed 30 m/s. Discus edge speeds reach 25 m/s, and hammer head speeds approach 30 m/s at release.

Ball Sports

Baseball pitching speeds vary by level: youth players 50-70 mph (80-113 km/h), high school 75-85 mph (121-137 km/h), college 85-95 mph (137-153 km/h), and professional 90-105 mph (145-169 km/h). The fastest recorded pitch exceeded 105 mph (169 km/h).

Tennis serve speeds show similar progression. Recreational players serve at 60-80 mph (97-129 km/h), while professionals regularly exceed 120 mph (193 km/h) for men and 100 mph (161 km/h) for women. The fastest recorded tennis serve reached 163.7 mph (263.4 km/h).

Team Sports Movement

Soccer players reach different speeds based on position and game situation. Walking pace is 0-2 m/s, jogging 2-4 m/s, running 4-5.5 m/s, high-speed running 5.5-7 m/s, and sprinting above 7 m/s. Elite players can exceed 10 m/s in full sprint.

Rugby players show position-specific speeds. Forwards typically reach 7-8 m/s maximum, while backs can exceed 9-10 m/s. During game play, high-intensity runs above 5 m/s occur 40-60 times per match for backs, 20-30 times for forwards.

Technical Considerations for Video Speed Analysis

Camera Setup and Calibration

Position your camera perpendicular to the plane of motion for accurate measurements. The entire movement path should be visible in frame. Include a reference object of known length (meter stick, cone spacing, lane marking) for calibration. Ensure adequate lighting to avoid motion blur, especially for high-speed movements.

Higher frame rates provide better temporal resolution. For walking or jogging, 30 fps is adequate. Running and team sports benefit from 60-120 fps. Sprinting and throwing events require 120-240 fps minimum. Impact events like golf or baseball hitting need 500+ fps for detailed analysis.

Measurement Accuracy Factors

According to sports science expert Robert Wood, who has analyzed sports performance data for over 25 years, several factors affect measurement accuracy. Perspective errors occur when the camera isn't perfectly perpendicular, causing apparent distance changes. Parallax errors arise when objects move at different distances from the camera. Motion blur reduces precision in identifying exact positions.

To minimize errors, use multiple camera angles when possible, mark reference points on the athlete or equipment, take multiple measurements and average results, and account for lens distortion in wide-angle footage.

Understanding Your Speed Results

Speed Classifications for Athletes

Walking speeds range from 1.0-1.5 m/s (3.6-5.4 km/h) for casual pace to 1.5-2.0 m/s (5.4-7.2 km/h) for brisk walking. Jogging occurs at 2.0-4.0 m/s (7.2-14.4 km/h), varying with fitness level.

Running speeds show wider variation. Recreational runners maintain 3.0-4.5 m/s (10.8-16.2 km/h), trained runners 4.5-5.5 m/s (16.2-19.8 km/h), and competitive runners exceed 5.5 m/s (19.8 km/h) for distance events. Sprint speeds range from 6-8 m/s for amateur athletes to 10-12 m/s for elite sprinters.

Contextualizing Your Measurements

Research by Robert J. Wood, PhD in Exercise Physiology from the University of Western Australia and founder of Topend Sports, indicates that speed capabilities vary significantly based on training status, age, and sport specialization. Youth athletes typically achieve 60-70% of adult speeds, developing progressively through maturation and training.

Masters athletes (35+ years) show approximately 1% annual decline in maximum speed from peak performance age (typically 25-30 years). However, well-trained masters athletes often outperform untrained younger individuals.

Practical Applications for Coaches

Training Zone Identification

Speed analysis helps establish training zones for athletes. Recovery runs should be at 40-60% of maximum speed, aerobic development at 60-75%, threshold training at 75-85%, VO2max training at 85-95%, and neuromuscular power above 95% of maximum speed.

For team sports, position-specific speed profiles guide training. Defenders might focus on repeated 5-10m accelerations, midfielders on sustained 20-40m runs, and forwards on maximum 30-50m sprints. Video analysis reveals actual game demands for individualized training.

Technique Analysis Benefits

Frame-by-frame analysis reveals technique inefficiencies invisible at full speed. Common findings include asymmetrical arm swing reducing speed by 3-5%, excessive vertical oscillation wasting energy, overstriding causing braking forces, and insufficient knee drive limiting stride frequency.

Advanced Video Analysis Techniques

Multi-Point Speed Tracking

Advanced analysis tracks multiple body points simultaneously. Center of mass velocity indicates overall body speed, hand speed reveals throwing or striking velocity, foot speed shows sprint mechanics efficiency, and hip velocity indicates power generation.

Data compiled by Robert Wood, PhD, shows that elite sprinters achieve hip velocities 85-90% of their maximum running speed, while recreational runners only reach 70-75%. This indicates better force transfer through the kinetic chain in trained athletes.

Acceleration Analysis

Beyond instantaneous speed, video analysis calculates acceleration rates. Elite sprinters achieve 8-10 m/s² initial acceleration, reaching 50% maximum speed within 2 seconds and 90% maximum speed by 4 seconds. Team sport athletes prioritize repeated acceleration ability over maximum speed.

Deceleration capabilities prove equally important, especially in sports requiring direction changes. Elite athletes decelerate at 6-8 m/s² under control, crucial for injury prevention and agility performance.