Calado started karting at cadet level in 1999 where he became a member of the 2000 championship-winning England Inter-Nations Cadet Team. He then went on to win the 2001 MSA British Cadet Championship and finish as runner up in the 2001 Super 1 National Comer Cadet Championship. He continued to kart through 2002 before placing as a runner up in the 2003 CIK-FIA European Junior championship. Calado also proceeded to take 3rd in the 2004 ICA Junior European championship. In 2005, he finished runner up in the ICA Italian Open Masters and won the ICA European Championship. He then went on to place as a runner up in the 2006 Formula A Macau International Kart Grand Prix and 3rd in the 2007 KF1 Andrea Margutti Trophy.
In 2008, James graduated to Formula Renault where he competed in the UK series for 20 races, taking 3 podiums and a single win to place 7th. He also raced in the Formula Renault 2.0 NEC for three races to place 25th. Calado also won both the Formula Renault UK Winter Cup where he took 3 podiums out of 4 races, two of which were wins, and the Portuguese Formuila Renault 2.0 Winter Series where he took four podiums out of four, winning three of them. He joined Fortec Motorsport for all four series. For 2009, he returned with the team to Formula Renault UK where he finished second with four podiums and 8 more wins to take 457 points. Calado also entered the Eurocup Formula Renault 2.0 with Fortec where he finished 17th. He then graduated to the British Formula 3 championship in 2010 with Carlin where he took 12 podiums, of which 5 were wins, to finish second in the standings. In 2011, Calado joined Louts ART for the GP3 Series where he took 6 podiums, of which one was a win, to finish second in the standings. He also competed in two races of the GP2 Final with the team, winning one of the races to place 5th in the standings.
Calado went on to complete two full seasons with Lotus GP/ART Grand Prix in 2012 and 2013 where he took two wins in each year, followed by another 5 podiums in each year to place him 5th and 3rd in the standings. In 2013 he also debuted in Formula One as a test driver for Sahara Force India F1 Team.
James debuted in endurance racing in 2014 when he joined AF Corse in the LMGTE Pro FIA World Endurance Championship. Out of the eight races he competed in, he took five podiums. In his rookie year, he placed 7th in the standings. He stuck with the team and competed in the championship in 2015, 2016, 2017, 2018-2019 and 2019-2020. He took 4th with 5 podiums in 2015, 3rd with 7 podiums, of which one was a win, in 2016, 1st with 7 podiums, of which 3 were wins, in 2017, 2nd with 3 podiums, of which two were wins between 2018 and 2019 and he currently sits at 2nd in the standings with a single win and a podium.
Calado also competed in the LMGTE Pro 24 Hours of Le Mans between 2015 and 2019 which he stuck with AF Corse for the entirety of his time. He took second in 2015 but didn’t manage to finish in 2016. He improved to 11th in 2017 and then to 7th in 2018. He finished first in his final Le Man’s race in 2019. In 2015, Calado also raced in the GT Asia Series with Clearwater Racing where he took a single podium out of his 3 races, finishing 25th in the standings and the LMGTE European Le Mans Series with JMW Motorsport where he finished 18th. Moving into 2016, James debuted in the GTLM WeatherTech SportsCar Championship with SMP Racing and Risi Competizione for once race each where he finished first with the later. Overall, he placed 19th in his rookie year.
He returned to WeatherTech with Risi for 2017 for two races to finish 18th in the standings. He also joined Kaspersky Motorsport for 5 races in the Blancpain GT Series Endurance Cup where he finished 7th. James also join Ferrari in the Intercontinental GT Challenge for 2017. Calado joined Risi again for WeatherTech in 2018, 2019 and 2020 where he took 7th, 20th and 6th. Between 2018 and 2019, Calado raced with CarGuy Racing in the Asian Le Mans Series where he won four out of four races to take the championship title. To finish off 2019, James entered to Blancpain GT Series Endurance Cup with AF Corse and Ferrari once more for the Intercontinental GT Challenge.
FIA Formula E
Calado made his debut in the FIA Formula E Championship in the 2019 to 2020 season with Panasonic Jaguar Racing, racing alongside his team mate Mitch Evans. He currently sits at 16th in the standings.