Frame Rate Converter

Frame rate (FPS) determines video smoothness and slow-motion speed.

Common frame rates:

• 23.976 fps: What “24p” actually means on most delivery formats
• 24 fps: Cinema standard (movies)
• 25 fps: PAL standard (European TV)
• 29.97 fps: NTSC broadcast standard (US, Japan), usually written 30
• 30 fps: True 30, common on cameras and phones
• 48 fps: High frame rate cinema (The Hobbit)
• 60 fps: Smooth video, gaming, sports
• 120 fps: Slow-motion (2x slower at 60 fps playback)
• 240 fps: Slow-motion (4x slower at 60 fps playback)
• 480 fps: Extreme slow-motion
• 960 fps: Super slow-motion (some smartphones)
• 1000+ fps: Scientific high-speed cameras

Slow-motion formula:

• Slowdown factor = Recording FPS / Playback FPS
• Example: 240 fps recorded, played at 30 fps = 8x slower

Frame interval:

• Time per frame = 1000 / FPS (in milliseconds)
• 30 fps = 33.3 ms per frame
• 60 fps = 16.7 ms per frame

The reason 24 fps still rules cinema isn’t a technical limit, it’s the look. That slight motion blur and judder reads as “film” to our eyes, while the same scene at 60 fps looks oddly smooth, the soap-opera effect that made The Hobbit’s 48 fps so divisive. Higher frame rates win for sports and gaming, where you want to track fast motion cleanly, and lose for drama, where a little blur feels cinematic.

Slow motion is where the math matters. You don’t slow footage by lowering the frame rate, you capture extra frames and play them back at a normal rate. Record at 240 fps, play at 30, and every second of action stretches to eight seconds, all of it smooth because there are real frames to show. Shoot at 30 and try to slow it down later and the software has to invent or duplicate frames, which is why “slow motion” pulled from a normal clip looks stuttery. Capture the frames up front; you can’t fake them well afterward.

The same formula runs backwards for timelapse. Record below the playback rate and the ratio flips: capture at 1 fps and play at 30 and you are not slowing anything down, you are speeding it up thirtyfold, so an hour of recording becomes two minutes. The arithmetic is identical, and the calculator above says which direction you are actually going rather than reporting a “0.03x slowdown” and leaving you to work out that this means 30 times faster.

If you also need the shutter speed to pair with a frame rate, the frame rate conform and shutter angle page works out the 180-degree shutter alongside the conform. This page stays on rates, clip length and frame count.

Why 30 is usually 29.97. When colour was added to NTSC in 1953 the frame rate was nudged down by a factor of 1000/1001 to keep the colour subcarrier from interfering with the audio. Broadcast “30 fps” has meant 29.97 ever since, and “24p” on most delivery formats means 23.976. The gap is a tenth of a percent, which sounds like nothing until you sync an hour of audio to it and end up 3.6 seconds adrift.