Estimate time to write a speech by word count.
Speech length converts to word count through speaking rate — around 130 words a minute for clear delivery, slower than conversational speech because a speech needs pauses. Dividing by drafting speed gives the first draft, and each subsequent draft costs roughly forty-five percent of the first because spoken prose is heavily rewritten for rhythm and breath, not just for content.
Word count
Words = speech minutes x speaking rate in words per minute
Writing effort
Total hours = words / drafting speed x (1 + 0.45 x (drafts - 1))
Roughly 1200 to 1500 at a clear delivery pace. Reading a 1800-word script in ten minutes means rushing, which audiences find hard to follow.
Writing it fully then reducing to notes is a good approach — the full draft fixes the argument and phrasing, while delivering from notes keeps it alive rather than read.