Video calculator: timecode, bitrate, file size and speech time

Conforming keeps every frame and changes the playback rate. Take an hour of 24p — 86,400 frames — and run it at 25, and it finishes in 57 minutes and 36 seconds. That is the PAL speedup: 4.17 percent faster, with the audio riding up about 0.71 of a semitone unless it is pitch-corrected separately.

Resampling keeps the duration and changes the frame count. The same hour needs 90,000 frames at 25, so 3,600 frames have to come from somewhere — duplicated, blended or interpolated. Which one you want depends on whether the delivery spec fixes the running time or the frame count. The calculator reports both, with the drift and the pitch shift, so the choice is deliberate rather than whatever the software defaulted to.

A narrator reads somewhere between 110 and 170 words a minute. Slow and deliberate sits near 110, an ordinary explainer voice near 140, a brisk promo read near 170. Three hundred words is therefore anything from 1 minute 46 seconds to 2 minutes 44 seconds — a full minute of difference on the same page of script, which is why the calculator shows all three paces at once instead of pretending there is one answer.

Count on the slower end for anything technical, anything with a number that has to land, or a read that needs to breathe between shots. Count on the faster end for a promo with hard cuts. Then read it aloud once against a stopwatch, because the only pace that matters is the one the person at the microphone actually uses.