What changes the result?
About 150 words per minute is a useful starting point, not an industry promise. Dialogue, comedy, suspense, poetry, footnotes, complex names and deliberate pauses can all slow a performance. A brisk non-fiction delivery may be faster.
Multiple performers do not automatically change the spoken duration, but duet and multicast work tends to add coordination and editing time. The displayed raw-recording range accounts for retakes and setup; the wider production range includes preparation, recording, editing, proofing, pickups and mastering.
Transparent methodology
Finished hours = word count ÷ words per minute ÷ 60. The low and high finished-duration range varies the selected speed by 7%. Raw recording is estimated at 1.7–2.8 hours for each finished hour, adjusted by production type. Total production uses 80–120% of the chosen editing multiplier, again adjusted for more complex casts. PFH cost applies the entered rate to the low and high finished-duration range.