Arm Speed Analyzer vs. DIY Slow-Motion Math
Free Video Calculation MethodFilming a throw at 240fps and counting frames from release to target is the original free way to estimate speed — and done carefully, it's a real physics calculation. Arm Speed Analyzer is also free, but automatic. Here's the honest tradeoff.
The Race
Raw mph Accuracy
Counting frames at 240fps from release to target and dividing distance by time is a genuine physics calculation of average flight speed — done meticulously, it's a real measurement. Arm Speed Analyzer's motion estimate is a different kind of number, built for trends rather than a one-off calculation.
Cost
Both use a phone you already own. Neither costs anything beyond that.
Effort Per Rep
Slow-motion math means filming every throw, then manually counting frames and calculating afterward — and remembering that release velocity runs about 7–8 mph faster than flight-averaged speed. Arm Speed Analyzer gives you a number immediately, no math required.
History & Trends
Slow-motion math gives you exactly one throw's worth of data for the effort of one calculation. Arm Speed Analyzer logs every session automatically and shows how your speed changes week over week.
Stays in the Flow of a Session
Frame-counting means stopping between throws to review the video. Arm Speed Analyzer shows a result right after the throw or swing, so training doesn't have to pause.
Which Should You Use?
Choose DIY Slow-Motion Math If…
you want a one-off, physics-based speed estimate and don't mind filming, reviewing footage, and doing the distance-over-time math yourself every time.
Choose Arm Speed Analyzer If…
you want automatic, ongoing tracking without stopping to do math after every throw or swing — and you want it to work the same way across sports.
Frequently Asked Questions
Is slow-motion frame counting actually accurate?
It can be, if done carefully — but it calculates average flight speed, not release speed, and a ball loses roughly 7–8 mph to drag between release and target. It also depends heavily on frame rate and precise distance measurement, so small counting errors swing the result noticeably.
Why use an app instead of just filming in slow motion?
Convenience over the course of a whole session. Slow-motion math gives you one number for the effort of filming, reviewing, and calculating one throw. Arm Speed Analyzer logs every rep automatically and shows trends over weeks, not just a single data point.
Track Your Arm Speed for Free
No setup, no subscription. Just your iPhone or Apple Watch.
