Video evidence
Video Speed and Frame Timing Calculator
Estimate speed across a known distance by identifying reproducible frame positions and a defensible time interval.
Method overview
speed = measured distance ÷ elapsed frame time
The worksheet converts frame count and frame rate into elapsed time, then applies the measured scene distance. It also exposes the sensitivity created by uncertain frame selection.
Evidence to document
- Original or verified working-copy frame rate.
- Start and end frames tied to identifiable scene positions.
- A scene distance established independently of the video image.
- Any dropped, duplicated, variable-rate, or interlaced frames.
Limitations
Displayed player timestamps and nominal frame rates can be misleading. Inspect the source file and document the exact timing method before relying on the result.
Record measurements, assumptions, units, rounding, and source material so another investigator can reproduce the result. See the methodology and validation center for verification policy and citation guidance.