Learning Retention Calculator

Hermann Ebbinghaus discovered that memory decays rapidly without reinforcement. The forgetting curve shows that:

• Within 1 hour: We forget about 50% of new information
• Within 24 hours: Retention drops to about 30%
• Within 1 week: Without review, only 20-25% remains

Spaced repetition interrupts this decay by reviewing material at optimal intervals, strengthening memory traces each time.