Using data of three well-observed type-II plateau supernovae ( SNe II-P ) , SNe 1987A , 1999em and 2003hn ; and two atmosphere models by Eastman et al .
( 1996 ) and Dessart \& Hillier ( 2005b ) we derive calibrations for bolometric corrections and effective temperature from BVI photometry .
The typical scatter of the bolometric correction is 0.11 mag .
With these results we obtain bolometric light curves and effective temperature evolution for a sample of 33 SNe II-P .
The SN sample shows a range of 1 dex in plateau luminosity and plateau durations from 75 to 120 days .
Comparing the shape of the transition between the plateau and the radioactive tail , we find that the size of the drop is in the range of 0.8 to 1.12 dex .