Free Video Length Calculator \u2014 Script Duration Estimator

The FlowShorts Video Length Calculator is a free tool that estimates how long your video will be based on your script, or tells you how many words you need for a target video duration. It supports two modes: Script to Duration (paste a script, get video length at slow, normal, and fast speaking paces) and Duration to Word Count (enter a target duration, get the required word count). The calculator also shows platform fit indicators for YouTube Shorts (60s), TikTok (15s, 60s, 3min, 10min), and Instagram Reels (90s), along with estimated scene counts. Ideal for video creators, scriptwriters, and anyone planning short-form content.

How It Works

Choose between two modes. In Script to Duration mode, paste or type your script and the calculator instantly shows the estimated video duration at three speaking speeds: Slow (120 WPM), Normal (150 WPM), and Fast (180 WPM). In Duration to Word Count mode, enter your desired video length in minutes and seconds, and the tool calculates how many words your script should contain at each speed. Both modes include platform fit indicators and estimated scene counts.

Platform Time Limits

YouTube Shorts allows up to 60 seconds. TikTok supports 15 seconds, 60 seconds, 3 minutes, and up to 10 minutes. Instagram Reels allows up to 90 seconds. The calculator checks your video duration against all these limits and shows a visual timeline so you can see exactly where your content falls relative to each platform maximum.

Scene Estimation

Short-form video typically uses one scene per 8-10 seconds to keep viewers engaged. The calculator estimates the number of scenes your video will need based on the calculated duration. This helps you plan your visual storyboard alongside your script, ensuring enough variety to maintain viewer attention throughout.