Methodology & sources
The math is simple and honest: we add each park’s current entrance fee times the number of separate trips you’ll make, then compare that total to the cost of the pass you qualify for. The pass “wins” once your total entrance fees would exceed its price. Free and discounted passes (Senior, Military, Access, 4th grade) are included with their current prices. Per-park fees and pass prices are taken from the official NPS pages below; each park in the picker links to its own nps.gov fee page.
Tool data REV . Refreshed periodically against nps.gov.