How many sheets can these trimmers cut at once?

Capacity varies widely. Personal rotary trimmers typically handle a handful of sheets per pass (the Dahle 508 is rated around 5), mid-range guillotines like the Swingline handle roughly 10 and the Westcott up to about 30, while dedicated heavy-duty guillotines advertise 300–400 sheets. Verified-purchase reviewers consistently note that real-world clean-cut capacity is lower than the maximum rating, so buy a step above your typical job.