Motor RPM Tachometer
Measure how fast a motor or shaft is turning from a short phone video — record it here or pick a clip you already shot. Everything runs on your phone; your video never leaves the device.
1 · Get a video of the rotating part
Aim at the spinning motor and press Record. You'll mark the spot after you stop. For fast motors, shoot in your phone's Slow-Mo mode and load it with “Pick a clip” — it reads much higher RPM.
Point at the spinning motor, drag a box over the mark, and the RPM updates live — no record/stop. Best for slower motors; for very fast ones, shoot in Slow-Mo and load it with “Pick a clip”.
Tip: shoot in your camera's Slow-Mo mode for motors above a few hundred RPM.
Tips for an accurate reading
- Put a strip of bright tape on the rotating part so there's a clear mark to track.
- Hold the phone steady and keep the mark inside the box the whole clip.
- Capture at least 2–3 seconds so several full turns are recorded.
- For motors faster than a few hundred RPM, use your phone's Slow-Mo mode, then load the clip here.
- Good light, low glare. Auto and Manual should agree within a few RPM.