Altius recorded 211 priced readings of nonstop business-class round trips from Frankfurt (FRA) to Detroit (DTW) booked 30 days out, across 106 departure dates between 2026-06-21 and 2026-10-04. Observed fares ran from US$4,531 to US$9,108. The lowest fare Altius scored on this window was US$4,531 for a 2026-10-21 departure, seen on 2026-09-21 — STRONG at the time, 19.6% below the US$5,636 this route was typically running that day.
A fare can move between our two readings of the same day, most often on the days furthest below typical. Where a day's two readings differ enough to matter, the chart marks that day and both readings can be read separately.