1/4 mile time converter

if you know your hp and how much your car weigh's give this a go and post if its close or way off ect ect

my old drift car did a 13.5 pass 1190 kgs ( on cams scales)with driver and just over 200hp atw's the converter was just off said it would do 13.7 going on the converter says my 1200ute sr should do a 11.8 seems a lil too good to be true .

wondering if the lower you get down in weight the more all over the place it gets

plz if you guessing your hp do say so cheers