Factorial ANOVA
Stage 1
Stage 2
$SS_{between \; As} = SS_A = \Sigma{\frac{{T_A}^2}{n_A}} - \frac{G^2}{N}$
$SS_{between \; Bs} = SS_B = \Sigma{\frac{{T_B}^2}{n_B}} - \frac{G^2}{N}$
$SS_{A X B} = SS_{between} - SS_A - SS_B $
$df=df_{A}=\text{number of levels of A} -1 $
$df=df_{B}=\text{number of levels of B} -1 $
$df_{A X B} = df_{between} - df_A - df_B $
See, F-distribution Table