What is the width of JWST's sunshield in meters?

The width of JWST’s sunshield is 14.162 meters.

That figure is the shorter of the sunshield’s two fully deployed dimensions. NASA gives the complete dimensions as 21.197 meters long by 14.162 meters wide, making the kite-shaped shield roughly the size of a tennis court.

The sunshield is central to Webb’s infrared mission. It blocks heat and light from the Sun, Earth, and Moon, allowing the telescope and its near-infrared instruments to cool passively in space. The shield has five separated layers of Kapton film, each coated to reflect and radiate heat toward space.

The length and width are easy to reverse, and rounded descriptions such as “about 14.6 by 21.1 meters” can appear in summaries. Those rounded values describe the same deployed structure. The precise stored value, 14.162 meters, is specifically the width; 21.197 meters is its length.