坎德拉每平方米（cd/m）是衡量亮度的国际单位制导出单位，其中的坎德拉是衡量发光强度的国际单位制主单位，平方米则是衡量面积的国际单位制导出单位。该单位旧称尼特（Nit，来源于拉丁语的“nitere”，意为照射），符号为nt。

坎德拉每平方米常用于标识显示设备的亮度，大多数厂家的桌面电脑的亮度均为200到300cd/m。SRGB色彩空间的显示器的亮度一般为80cd/m。高清晰度电视的亮度则在450到1000cd/m之间一般的校准显示器的亮度为120cd/m。

The candela per square metre (cd/m) is the derived SI unit of luminance. The unit is based on the candela, the SI unit of luminous intensity, and the square metre, the SI unit of area.

As a measure of light emitted per unit area, this unit is frequently used to specify the brightness of a display device. Most consumer desktop liquid crystal displays have luminances of 200 to 300 cd/m; the sRGB spec for monitors targets 80 cd/m. High-definition televisions range from 450 to about 1000 cd/m. Typically, calibrated monitors should have a brightness of 120 cd/m.