Billboard predicts the king of pop will open with 400,000 to 500,000

Justin Bieber's Believe album is on course to net the singer his best sales week yet -- and the biggest debut of the year.

Industry sources suggest that the set, which came out today (June 19), may sell between 400,000 to 500,000 copies by the end of the tracking period on June 24. (However, it's still very early in the week, so those sales projections will change on a daily basis.)

If Believe does sell in the 400,000 to 500,000 range, that would easily secure Bieber his largest sales frame yet. His highest week thus far came when My World 2.0 sold 291,000 in its second week on the chart in April, 2010.

Believe could also land the largest debut this year for an album. It would surpass the start of Madonna's MDNA, which launched with 359,000 according to Nielsen SoundScan. (The best sales frame overall in 2012 was registered by Adele's 21 in the wake of her multiple Grammy Awards wins in February. It sold 730,000 in the week after the Grammy show.)

Believe will most certainly open at No. 1 on the Billboard 200 chart next week. If it does, it will be his fourth chart-topping set, following My World 2.0, Never Say Never: The Remixes (EP) and Under the Mistletoe.

The final sales figures for Believe will be released on Wednesday, June 27.