Got this figures from a UKMIX forum "U2 album sales?"
Figs, from the Best selling artist thread, thanks to MJDangerous for them. I updated 18singles sales to 4.5m shipped, as it has sold 4m.
* Boy (1980,~3.8 million copies)
* October (1981, ~3.7 million)
* War (1983, ~9.5 million)
* The Unforgettable Fire (1984, ~8 million)
* The Joshua Tree (1987,~28 million)
* Rattle and Hum (double album, 1988,~14.5 million (29m discs))
* Achtung Baby (1991, ~17.5 million)
* Zooropa (1993, ~7.5 million)
* Pop (mars 1997, ~7 million)
* All That You Can't Leave Behind (2000, ~12 million)
* How to Dismantle an Atomic Bomb (2004, ~10 million)
* Under a Blood Red Sky (concert, 1983,~9 million)
* Wide Awake in America (mini-album, 1985, ~ 2.5 million)
* The Best of 1980-1990 (compilation, novembre 1998, ~16.5 million)
* The Best of 1990-2000, 2002 (compilation, ~6.5 million)
* U218 Singles (compilation, novembre 2006, ~4.5 million)
Total:160.5 million.
So MJDangerous claims to have these figures. And these figures are almost the same as the estimate figures by Edge3 and Sting2.