FREE STUDY TOOL
Forgetting Curve Simulator
New material becomes harder to recall when it is not revisited. Choose up to five review days and compare a simple no-review curve with a curve that resets and strengthens after each review.
Free, no sign-up, no ads, and fully browser-based
How to use it
- 1
Confirm the study date and choose up to five review intervals.
- 2
Compare the reviewed and no-review lines across the 60-day chart.
- 3
Copy a shareable URL or download the current chart as a PNG.
How this forgetting curve model works
The simulator uses the exponential model R=exp(-t/S), where t is the number of days since study or the latest review and S represents memory strength. Each review resets the displayed retention to 100% and multiplies strength by 2.5, making the next decline slower. This is an educational model for comparing schedules, not a measurement of your personal memory. Difficulty, prior knowledge, sleep, attention, and successful recall all change real retention.
Ebbinghaus studied his own learning of meaningless syllables, so the famous curve is not a universal timetable for every learner or subject. The more durable lesson is that spacing practice and actively retrieving an answer generally work better than concentrating all exposure in one sitting. Memly uses FSRS 6.0 with 21 parameters and your answer history to adapt each card's interval. Use this chart to explore the idea, then adjust a real schedule based on performance.
Frequently asked questions
What is a forgetting curve?
It is a model showing that recall tends to become harder as time passes after learning. It describes a tendency, not a fixed percentage that applies equally to everyone.
When should I review?
There is no universal interval. One, three, and seven days are practical starting points, but difficult items should return sooner and easy items can wait longer.
Are the percentages my real retention?
No. They are estimates from a simplified formula that does not test your understanding. Use them to compare schedules rather than diagnose memory.
Can I use the chart in teaching material?
Yes. Download the PNG and note that it is a simplified Memly model rather than a direct reproduction of an individual's measured forgetting.
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Learn the method behind the tool
Results are planning estimates. Prefer official exam, school, and testing-provider information when making decisions.
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