Its estimated operating costs were $3,800 per block hour in 1972 (equivalent to $24,617 in 2021), compared to actual 1971 operating costs of $1,835 for a 707 and $3,500 for a 747 (equivalent to $12,278 and $23,419, respectively); for a 3,050 nmi (5,650 km) London–New York sector, a 707 cost $13,750 or 3.04¢ per seat/nmi (in 1971 dollars), a 747 $26,200 or 2.4¢ per seat/nmi and Concorde $14,250 or 4.5¢ per seat/nmi.[198] Concorde's unit cost was then $33.8 million[199] ($162 million in 2020 dollars[200]).