Estimate interview transcript length.
Transcript length is speaking time multiplied by pace, and the correction that matters is silence. Conversational interviews contain 15 to 25 percent pauses, thinking time and cross-talk that produces no transcribable words, so a 45-minute recording yields around 37 minutes of speech. At a conversational 150 words per minute that is roughly 5500 words, or 22 double-spaced pages at the standard 250 words per page. Splitting out the interviewee's share is useful for qualitative research, where the ratio of interviewer to participant talk is itself a quality measure — a good interview is heavily weighted toward the participant.
Transcript words
Words = interview minutes x (1 - silence share%) x speaking pace
Transcript pages
Pages = words / 250 at standard double spacing
Because pauses produce no words but consume clock time. Interviews naturally contain thinking pauses, question gaps and overlapping speech that transcribes to little. Ignoring that inflates a word estimate by 20 percent or more, which matters when you are quoting transcription costs.
In qualitative research it is a direct quality signal. A skilled interviewer asks short open questions and lets the participant speak, so 75 to 85 percent participant talk time is the target. A transcript approaching 50/50 usually means leading questions or the interviewer filling silences.