The Humanevi newsletter
Weekly
Once a week: 5 things worth your time.
1 story, 1 idea, 1 discovery, 1 tool, 1 book.
The Humanevi newsletter
Once a week: 5 things worth your time.
1 story, 1 idea, 1 discovery, 1 tool, 1 book.
Without review, memory of something new fades fast — that's why spaced repetition works so well.
| Time since learning | Estimated retention |
|---|---|
| Right after learning | 100% |
| 1h later | 97% |
| 9h later | 74% |
| 1 days later | 45% |
| 2 days later | 20% |
| 3 days later | 9% |
| 7 days later | 0% |
| 30 days later | 0% |
Reviewing the material at increasing intervals — hours, then days, then weeks — interrupts this drop and locks in memory far more efficiently than re-reading everything at once.
This is a simplified illustration based on the general shape of Ebbinghaus's forgetting curve, not a measurement of your own specific memory.
A visualizer that shows, in a table and chart, how your memory of something newly learned fades over time when you do not review it. It suits students and professionals who want to understand why they forget so much after a class or reading, and why reviewing at intervals helps.
The tool uses a simplified exponential decay in the style of the Ebbinghaus curve. Estimated retention is 100% times e raised to minus the time in hours divided by 30 (24 hours times a constant of 1.25 built into the code). It computes that value for fixed points: right after learning, 1h, 9h, 24h, 48h, 72h, 168h and 720h. It is an illustration, not a personalized model.
From the tool's points: right after learning, 100%. After 1 hour, about 96.7%. After 9 hours, 74.1%. After 24 hours, 44.9%. After 48 hours, 20.2%. After 72 hours, 9.1%. At 7 days (168 hours), under 1%. The drop is steepest early on, which is why reviewing soon makes sense.
This is a simplified illustration, not a measurement of your memory. Real forgetting speed depends on the material, sleep, interest and how you studied. It is not a memory assessment.
