On the web2 calc use arc tan. It is the same as inverse tan.
atan(7/12)
$$\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{tan}}^{\!\!\mathtt{-1}}{\left({\frac{{\mathtt{7}}}{{\mathtt{12}}}}\right)} = {\mathtt{30.256\: \!437\: \!163\: \!529^{\circ}}}$$
.
