Charlotte Wankel was educated at Harriet Backer’s (1845–1932) school for painting in Kristiania (now Oslo) during the period 1906–1909. In 1909, she travelled to Paris with her sister Frida Wankel (1886–1982), where she enrolled at the Académie Matisse in 1910. Her early paintings were developed in a realistic style, though she took inspiration from fauvism. After spending the war years in Norway, she returned to Paris in 1922 and took a strong interest in l’Esprit Nouveau.
She soon turned towards constructivism and cubism. She was inspired by cubism and Georges Braque (1908–1963). She studied under Pedro Luiz Correia de Araújo (1884–1955) in 1922. Together with Ragnhild Keyser (1889–1943) and Ragnhild Kaarbø (1899–1949), C. Wankel became part of the international circle of avantgarde artists in Paris in the 1920s. All three of them joined the Académie Moderne in 1925, where C. Wankel joined the classes of both Fernand Léger (1881–1955) and Amédée Ozenfant (1886–1966). Her Maleri [Painting, 1925], is one of her many works merging F. Léger’s modernist machines and the purism of A. Ozenfant. This abstract composition is centred on the tension between tube-like, rectangular and circular flat forms in various shades of grey, brown and blue in a composition free-floating on a beige undefined space or background. Her abstract compositions are precise with overlapping geometric shapes. In paintings such as Komposisjon [Composition, 1927], C. Wankel also plays with the human figure, with abstract body fragments as part of an architectural or constructivist scheme. Her colour scheme is often related to purism: greyish tones of blue, brown, ochre and pale shades of yellow and pink.

C. Wankel developed her style in new directions throughout her career. In the 1920s, she explored portraiture painting. In the 1930s, her paintings were figurative with simplified compositions. This can be found in Gutt med agurkranker [Boy with a cucumber plant, 1930]. From this period onwards, her nonfigurative work is less constructivist, drawing inspiration from surrealism and Vassily Kandinsky’s (1886–1944) later works.

In 1925 her work was shown at the exhibition Art d’aujourd’hui in Paris alongside eighty-seven international avantgarde artists. At her initiative, the exhibition Otte skandinaviske kubister [Eight Scandinavian Cubists] was put together at Kunstnerforbundet in Oslo in 1927. This exhibition, along with C. Wankel’s solo exhibition in the same venue in 1930, and the group exhibition she took part in at the Blomqvist Art Gallery in 1934, were received unfavourably, as most Norwegian critics during the interwar years were hostile to cubism and nonfigurative painting. In 1935 she took part in the International Women’s Art Exhibition organised by the Women’s International Arts Club in London, and in 1937 the Paris’ Exposition Internationale des Arts et Techniques dans la Voie Moderne.

Her works are in the collections of the Nasjonalmuseet for kunst, arkitektur og design, Oslo, the Trondheim Kunstmuseum and private collections.