Overview: Frame rates

Frame-rate descriptions express the frequency and regularity of pictures along a video's timeline.

“Thirty frames per second” can conceal a rounded rate, a precisely fractional rate or a varying sequence of intervals. Those differences matter when comparing durations and matching a display cadence. This group covers the rate itself and the two common reasons a simple whole-number label is incomplete.

• Video frame rate
  Video frame rate describes how many complete pictures are presented per second.

• Fractional frame rates: 23.976, 29.97, and 59.94
  These familiar fractional frame rates are exact integer rates divided by 1.001.

• Variable frame rate
  Variable frame rate allows the interval between successive video pictures to change.