Solar flux unit

The solar flux unit (sfu) is a non-SI unit of spectral flux density often used in solar radio observations, such as the F10.7 solar activity index. It is equivalent to 10⁻²² watts per square metre per hertz (SI), 10⁻¹⁹ ergs per second per square centimetre per hertz (CGS), and 10⁴ Jansky.^[1]

solar flux unit
Unit system	non-SI metric unit
Unit of	spectral flux density
Symbol	sfu
Conversions
1 sfu in ...	... is equal to ...
SI units	10−22 W⋅m−2⋅Hz−1
CGS units	10−19 erg⋅s−1⋅cm−2⋅Hz−1