Do the arithmetic once
Say the season runs from January 20 to April 15, about sixty working days. At a sustainable forty hours a week that is roughly 480 hours per preparer. If a 1040 in your firm truly takes two and a half hours end to end, counting review, document chasing, and the back-and-forth, that is about 190 returns per preparer before entity work, extensions, and everything that isn't preparation. Change any input and the number moves, which is exactly the point: your capacity comes from your mix, your process, and your people, not from an industry average.
Why firms overestimate
The common mistakes all point the same direction. Last year's maximum gets treated as capacity, when it was actually the overload that made the season miserable. Preparation time gets counted while review and chasing don't, and those are often half the total. Weekends get treated as a plan instead of a failure mode. And extensions get counted as relief, when they move work to September and October rather than removing it.
The number that matters is per deadline
Annual capacity is a comfortable fiction. The real question is whether the work due by March 15 fits the hours before March 15, whether the April 15 pile fits the crunch, and whether extension season quietly has more in it than it can carry. A firm can look fine on the year and be over capacity at every single deadline.
Run your number
The free Capacity Check does this arithmetic for your actual book in ninety seconds, with the extension deadlines counted, and shows you where the work really lands.
Run the Capacity Check
Your book, your hours, your deadlines. Free, and it runs in your browser.
Run the Capacity Check