How many hours should I study per day for class 12 board exams?

Quality beats quantity. 4-5 focused hours with active recall beats 8 hours of passive reading. A good schedule: divide subjects by weak/strong. Spend 60% on weak subjects, 40% on revising strong ones. Use the Pomodoro method: 45-minute focused study followed by 10-minute break. Most toppers studied 6-8 effective hours. Do not compare with friends. Test yourself with past year papers every weekend from now. Sleep 7-8 hours — memory consolidation happens during sleep. Two months before exams, do only previous year papers and timed mock tests.