How to use the AI Rep Counter
- Pick an exercise, enter your weight for the calorie estimate, and set reps per set and number of sets.
- Press “Start camera” and place the device 2–3 m away, side-on or facing you, with head to ankles visible.
- Start moving: each full rep adds one and is announced, and form cues appear when your technique slips.
- Rest starts automatically between sets. Save the workout to on-device history and export it as CSV.
How does the AI count reps?
The page loads Google’s MediaPipe Pose Landmarker and finds 33 body landmarks (shoulders, elbows, wrists, hips, knees, ankles and more) in every frame, then measures joint angles. For a squat, a knee angle falling from about 170° to below 100° marks “down” and rising back above 160° marks “up”; only the full cycle counts. Smoothing and a minimum rep duration stop jitter and half reps from being counted.
Where should I put the camera?
Film squats, lunges, sit-ups and push-ups from the side so knee, hip and elbow bends are clear. Jumping jacks, high knees and curls work facing the camera. Keep the device around waist height, 2–3 m away, with a plain background and light in front of you. Clothing that contrasts with the background helps.
How are calories estimated?
We use metabolic equivalents (METs) from the Compendium of Physical Activities: kcal per minute = MET × 3.5 × body weight (kg) ÷ 200, multiplied by your active time. Body-weight training is roughly 2.8 MET light, 3.8 moderate and 8.0 vigorous. These are population averages, so your actual burn varies with fitness, range of motion and heart rate. Treat the number as a trend, not a measurement.
Which form cues are included?
Squats: not deep enough, knees caving in, leaning too far forward. Push-ups: sagging or piked hips, not lowering enough. Lunges: back knee not dropping. Curls: not fully extending. Cues rely on joint-angle thresholds and catch obvious issues only; they do not replace a coach.
Privacy and safety
Camera frames are analysed in browser memory one at a time and are never recorded, stored or uploaded. History lives only in this browser. Warm up first and stay within your limits; if you have joint injuries, heart conditions or are pregnant, ask a doctor before exercising.
Frequently asked questions
Do I need to install an app?
No. It runs in the web page. The first run downloads about 15 MB of pose model and runtime, which is then cached.
Why are some reps not counted?
Usually your body is not fully in frame, the range of motion is short (not squatting deep enough or not standing all the way up), or the room is too dark. Move the device back or raise the sensitivity setting.
Which exercises are supported?
Squats, push-ups, jumping jacks, lunges, sit-ups/crunches, bicep curls and high knees. Use the Plank Timer for planks and the Yoga Pose Checker for yoga.
Can it count several people?
Not yet. It tracks the most prominent person; several people in frame can confuse the count.
Is the calorie number accurate?
It is an estimate from the MET formula and your weight and can be off by ±30% or more. It does not replace a fitness tracker or heart-rate strap and is not medical data.
Does it work on a phone?
Yes, with the front or rear camera. Turn the phone sideways on a stand. Low-end phones may run at a lower frame rate and miss very fast moves like jumping jacks.