How much do 2 stops (and a half) equal?

[Cristina S]

If 1 stop is 2x, I mean we have twice the light...

Do 2 stops equal 4 times the light? And 1 stop and a half, 3 times?

If so, does 2 stops and a half (more or less the difference from 2/3" to S35) mean to amplify 6 times the exposure?

[Julio Quintana]

1 stop = 2^1 = 2 times the light
2 stops = 2^2 = 4 times the light
2.5 stops = 2^2.5 = 5.66 times the light
3 stops = 2^3 = 8 times the light