John Glencross co-founded the venture capital company Calculus Capital 25 years ago after a career in investment banking. Across its various activities, Calculus invests in technology, healthcare and media. John leads the firm and heads its media investment activities. Calculus has investments in UK and international production companies, including Jude Law's Riff Raff Entertainment, David Abraham's Wonderhood Studios, Brouhaha Entertainment and Raindog Films founded by Ged Doherty and Colin Firth.

Recent productions include the Netflix global hit Boy Swallows Universe, Black Rabbit starring Jude Law and Justin Bateman for Netflix, the feature films Lee with Kate Winslet, Firebrand with Jude Law and Alicia Vikander, Eleanor the Great which marks Scarlett Johannson's directorial debut, Gurinder Chada's Christmas Karma and the BAFTA and Grierson nominated series Evacuation: Escape from Kabul. Earlier this year, Calculus took over Great Point's media financing business, which provides cashflow financing for television productions, including Small Axe, Brexit: The Uncivil War with Benedict Cumberbatch, alongside Golden Globe and BAFTA-winning Conclave and BAFTA-winning Kneecap.