Controlling LLM Prose

How-to guide

How to hit a target reading time

Problem: You need output that reads in a fixed number of minutes, not an arbitrary word count.

Use when: Summaries, briefs, release notes, anything with an attention budget.

Steps

  1. Pick the reader’s speed band: ~275 WPM casual, ~220 standard, ~140 dense/technical.
  2. Multiply the band by your target minutes to get a word budget (e.g. 220 × 3 = 660).
  3. State the budget as a range (±8%) plus the WPM and complexity in the prompt.
  4. Ask the model to prioritize readability so it does not pad to hit the number.

Example

Weak promptSummarize this in a few paragraphs.
Calibrated promptSummarize for a 3-minute read at Moderate complexity: 610–710 words at ~220 WPM. Prioritize clarity over hitting the exact count.