Slow-Motion Time Stretch Calculator

How to Use the Slow-Motion Stretch Calculator

  1. Enter your capture frame rate. This is the fps your footage was originally recorded at (e.g., 120 fps, 240 fps, 1000 fps).
  2. Enter your playback frame rate. Choose the fps of your project timeline or delivery format (e.g., 24 fps, 30 fps, 60 fps).
  3. Enter the clip duration. Input how long the action actually lasted in real time (seconds or minutes).
  4. Click Calculate. The tool will instantly show you:
    • The slowdown factor (how many times slower your footage will appear).
    • The new clip duration when conformed to your playback fps.
    • The total frame count captured.
    • The percentage change in playback speed.
  5. Use the result to plan whether your slow-motion is dramatic enough for the project, and how much footage you’ll end up with in your edit.

Tip: Higher capture frame rates create smoother slow-motion but require more light and produce larger file sizes. Always balance your frame rate, shutter speed, and exposure when planning slow-motion shots.

Slow-Motion Time Stretch Calculator

Understanding Slow Motion & Time Stretch in Video

Slow motion is one of the most powerful storytelling tools in filmmaking, allowing audiences to experience moments with heightened drama, clarity, and emotion. Technically, slow motion is created by recording footage at a higher frame rate than the playback frame rate. When that footage is conformed to a standard timeline, the action is stretched out, appearing slower than real life.

The Slow-Motion Stretch Calculator makes it easy to see exactly how your capture and playback frame rates affect your footage. For example, recording at 120 fps and playing back at 24 fps creates a 5× slowdown. A one-second event in real life becomes five seconds on screen. Capture at 240 fps and play back at 30 fps, and you’ll achieve an 8× slowdown — turning a brief action into a long, dramatic sequence.

This calculator is especially valuable for:

Slow motion comes with technical trade-offs. Higher frame rates require faster shutter speeds to avoid motion blur, which means you’ll need more light on set. They also generate much larger file sizes, filling memory cards and drives quickly. By using the calculator, you can balance creative goals with the practical limits of lighting, storage, and editing.

Whether you want a subtle 2× slow-down for smooth cinematic feel or extreme 1000 fps super slow-motion for scientific analysis or dramatic effects, this tool gives you the numbers you need to plan ahead. Instead of guessing, you’ll know exactly how long your slowed-down clip will be, how many frames you’re working with, and whether it fits your timeline.