How many lumens do I actually need in a headlamp?

For around-camp tasks, reading, and short walks, 100–300 lumens is plenty and is what most reviewers recommend for general use. Trail runners and night hikers typically want 350–500 lumens of sustained output, and ultrarunners or technical terrain users push toward 800–1,100 lumens. Note that specialist communities repeatedly point out that headlining 'max lumen' figures often can't be sustained because the lamp thermal-throttles down within minutes.