What shutter speed should I use when shooting slow motion?

Follow the 180-degree shutter rule: set your shutter speed to double your capture frame rate. For example, shoot at 1/120s shutter speed for 60 fps, and 1/240s shutter speed for 120 fps to maintain natural motion blur.

What happens if I slow down 24fps footage to 50% speed?

Slowing 24fps footage down without shooting at higher frame rates forces the editing software to either duplicate frames (causing visible stutter) or generate artificial in-between frames using optical flow AI (which can cause distortion warping).

Media & Images

Slow-Motion Video Speed Percentage Calculator

The problem: Dialing in arbitrary speed percentages in Premiere or DaVinci Resolve causes frame stutter or unnecessary optical flow artifacts.

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Playback Speed

20%

Set speed in NLE timeline

Slowdown Factor

5×

Time dilation multiplier

Timeline Duration

25s

From 5s recorded footage

Pacing Quality

Dramatic Cinema Slow Motion (Dreamlike pacing)

1:1 camera-to-project cadence

Camera Capture Frame Rate

Recorded FPS120 FPS

Popular Camera Rates:

Project Timeline & Clip Length

Editing Project Frame Rate

Recorded Clip Duration (Seconds)

NLE Workflow Tip

In Premiere Pro: right-click clip > Modify > Interpret Footage > Assume this frame rate: 24 fps, or in DaVinci Resolve set Clip Speed to 20%.

Slow-Motion Video Speed Percentage Calculator: the complete guide

A Slow-Motion Video Speed Percentage and Duration Calculator calculates exact playback speed adjustments and clip duration stretches for high frame rate footage on standard editing timelines. Filmmakers and videographers shooting at 60fps, 120fps, or 240fps on Sony, Canon, RED, or iPhone cameras must dial in exact percentage values in Premiere Pro, DaVinci Resolve, or Final Cut Pro to achieve organic 1:1 slow motion without frame blending or stutter.

The Physics of In-Camera Overcranking

In cinema terminology, shooting at a frame rate higher than the delivery rate is called 'overcranking'. When a camera captures 120 frames per second and those frames are played back sequentially at 24 frames per second, action appears five times slower than real life. The exact mathematical playback speed percentage is: Speed % = (Timeline FPS / Recorded FPS) × 100.

Interpreting Footage vs. Speed Retiming

In modern non-linear editors (NLEs), filmmakers can either set clip speed to the calculated percentage (e.g. 20% for 120fps on 24fps) or use 'Interpret Footage' to change the clip's native timebase. Interpreting footage guarantees that every single recorded sensor frame maps directly to one timeline frame, producing crystal-clear motion without optical flow artifacts.

Step by step: how to use Slow-Mo Speed %

1
Select or input your camera's high-speed capture frame rate (e.g., 60, 120, or 240 fps).
2
Choose your project's timeline frame rate (e.g., 24.0 fps Cinema, 25.0 fps PAL, or 30.0 fps Web).
3
Enter the length of your recorded video clip in seconds.
4
Read the exact playback speed percentage (e.g., 40.0% for 60fps on 24fps).
5
Inspect the total stretched timeline duration and pacing quality classification.
6
Apply the percentage directly in your NLE clip speed dialogue.

Security & privacy

All framerate conversions and speed ratio formulas execute 100% locally in your browser tab. No footage or camera metadata is uploaded.