2024 round of the
2024 ADAC GT Masters season Kalender retained
ADAC support for 2024 but switched to
ADAC GT Masters, partnering
Elias Seppänen at Landgraf Motorsport. Finishing runner-up on his series debut at
Oschersleben, Kalender then missed out on race two pole by 0.031 seconds but rebounded to take his first win of the season. In the following round at
Zandvoort, Kalender extended his points lead by winning race one from pole position. Missing out on race one pole by 0.076 seconds at the
Nürburgring, Kalender initially fell to seventh, but as
Elias Seppänen got in the car, he was able to gain five positions and finish second. In race two, Kalender was fighting for the podium but a late-race collision sent him back to sixth. In the following round at
Spa-Francorchamps, Kalender won from pole position in race one, and initially won race two, but were classified sixth after being given a penalty. At the
Red Bull Ring, Kalender finished third in race one after having started 11th, while in race two he was able to maintain the lead of the race until the end to take his fourth win of the season. In the final round of the season at the
Hockenheimring, Kalender finished third in race one to win the
ADAC GT Masters title with a race to spare. In the season finale, Kalender overtook Alexander Schwarzer at the hairpin following a safety car restart, to take his fifth win of the season. Kalender also made one-off appearances for
Madpanda Motorsport in both the
GT World Challenge Europe Endurance Cup and the
GT World Challenge Europe Sprint Cup.
2025 in 2025 On February 12, it was announced that Kalender would step up to
DTM with Landgraf Motorsport, alongside
Lucas Auer, in his first year as a
Mercedes-AMG junior driver. In his rookie year in DTM, Kalender scored his first points in race two at the
Lausitzring by finishing 15th, before scoring points in all but six races to end the year 21st in points with a best result of fifth at the
Hockenheimring. During 2025, Kalender also made one-off appearances in the ST-X class of the
Super Taikyu Series for
Craft-Bamboo Racing, and the Silver Cup of the
GT World Challenge Europe Endurance Cup for GetSpeed. At the end of the year, Kalender finished second in the
Indianapolis 8 Hour for
Mercedes-AMG Team GMR.
2026 Kalender was retained as a
Mercedes-AMG junior driver for 2026, as he remained with Landgraf Motorsport for his sophomore year in
DTM and a campaign in the
GT World Challenge Europe Endurance Cup for GetSpeed. ==Karting record==