Altius recorded 308 priced readings of nonstop business-class round trips from Washington (IAD) to Brussels (BRU) booked 90 days out, across 138 departure dates between 2026-05-20 and 2026-10-04. Observed fares ran from US$5,074 to US$6,946. The lowest fare Altius scored on this window was US$5,074 for a 2026-08-18 departure, seen on 2026-05-20 — STRONG at the time, 15.9% below the US$6,033 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.