[1] Mačiulis spent two years competing in the LKAL, the Lithuanian League 2nd Division.

Mačiulis made his pro debut in 2004, with the Lithuanian League team Nevėžis.

[2] Mačiulis averaged a career-high 14.0 points and 5.0 rebounds per game in the 2008–09 season in the Euroleague.

[7] In his first game back after his injury, against Kalev/Cramo, he scored 16 points, grabbed 2 rebounds, and led Baltai to a victory.

[9] On 24 July 2012, he signed a one-year deal with the Greek League team Panathinaikos.

[15] He was also voted Lithuanian Player of the Year, for the first time in his career, in 2015, along with Gintarė Petronytė.

[19] On 6 March 2018, Mačiulis signed with Lokomotiv Kuban of the Russian VTB United League.

In the EuroBasket 2013, Lithuania was runner-up, and Mačiulis played one of the best games of his career with national team, in the semi-finals against Croatia.

On 13 September 2015, in the eighth-finals game against Georgia, Mačiulis lead his team to an 85–81 win, posting tremendous numbers: 34 points, 6 rebounds, 3 assists, 4 steals, and 2 blocks.

[28] Following his retirement, Mačiulis became a consultant for Nevėžis Kėdainiai of the Lithuanian Basketball League (LKL).