Road Speed Calculator

Estimate speed from dashcam footage by timing the gap between dashed lane marks. This calculator assumes one interval is 40 feet.

1. Start your video and pause right before a lane dash reaches the edge of frame.
2. Press MARK each time the next dash reaches that same point.
3. Use at least 3-5 marks for a stable average speed.

First press sets a start point. Second press begins speed calculation. Spacebar also triggers MARK.