# Relativistic mass of photon [duplicate]

What is the relativistic mass of one photon, i.e. what is $$N$$ here: $$10^{-N}$$ kg?

• Photons don't have mass. Can you elaborate on your question more? – Aaron Stevens Sep 23 '18 at 17:07
• Photon in rest doesn't have rest mass, but still must have relativistic mass by $E=mc^2$.If $E$ is not zero as it is in fact not, $m$ cannot be zero as well. – user2925716 Sep 23 '18 at 17:10
• For photons $E=pc$. They have momentum, but not mass. – Aaron Stevens Sep 23 '18 at 17:14