As of 2008 these are the latest Soundscan US sales numbers which is from 1991-2008
1. Garth Brooks, 68,051,000
2. The Beatles, 56,683,000
3. Mariah Carey, 51,370,000
4. Celine Dion, 50,167,000
5. Metallica, 50,111,000
6. George Strait, 40,201,000
7. Tim McGraw, 37,171,000
8. Alan Jackson, 36,201,000
9. Pink Floyd, 34,986,000
10. Shania Twain, 33,672,000
11. Kenny G, 33,340,000
12. Eminem, 33,078,000
13. U2, 32,473,000
14. Backstreet Boys, 30,655,000
15. Elvis Presley, 30,042,000
The RIAA indicates that total US sales are approximatly 55 million since Boy in the US.
In the 80s the US seemed to make up about 50 percent of U2s album buying public but in the 90s and today that has changed to about 33 percent.
Based on the RIAA number it can be assumed that U2 sold approximatly 23 million albums in the US within the decade of the 80s and with the assumption of that being 50 percent of the sales within the 80s I am assuming that U2 sold approximatly 46 million albums worldwide within that decade.
Based on the fact that U2 has sold about 32 million in the US from 1991-2008 and that being 33 percent of the sales since then tje rest of the world has sold approximatly 64 million since 1990.
The new album up until this date has sold approximatly 2 million worldwide so by my calculations we have:
46 million + 96 million + 2 million = 144 million albums.
That is my best guess as to approximate sales.
I think realistically it could be anyplace between 140-160 million.