Nitcd/m²
Also: candela per square metre
A nit is the practical name for the unit of luminance, candela per square metre: 1 nit = 1 cd/m². It is the quantity that comes closest to what people call “brightness”.
An indoor LED screen typically reaches 600–1,000 nits; an outdoor screen that must stay legible in full sunlight, 5,000–7,500 nits. Luminance does not depend on viewing distance, which is why nits are the right measure for comparing screens with one another.