Circular is a geometric sans-serif typeface created by Swiss designer Laurenz Brunner and released through Lineto in 2013. Circular is Brunner’s second official release, the other being the well-received Akkurat. Although the design is based primarily off geometric forms, Circular has quirks that give it a lot of warmth. I think the design of the lowercase t is very distinctive and makes Circular easy to identify compared to other geometric sans-serifs. Circular is available in four weights—book, medium, bold and black—each with matching italics.
Font research done for you.