Vocabulary after one week
- Input
- 7 days since learning, 1 review
- Result
- Estimated retention around 67%
- Action
- Review tomorrow to keep the memory active.
Measure time-based loss
Forgetting Curve Calculator
Estimate how much you may remember over time and get a simple review suggestion based on a forgetting curve.
Estimate memory retention and decide when to review next.
Retention65.8%
Next reviewtomorrow
Scoring logic
Forgetting curve estimate
Retention decreases over time and improves with reviews. This tool uses days since learning and completed reviews to estimate review urgency.
Days since learning
Longer gaps usually lower retention.
Reviews completed
Each review slows the decay curve.
Retention estimate
Use the result to choose today, tomorrow, or later review.
Sample results
Exam topic after two weeks
- Input
- 14 days since learning, 0 reviews
- Result
- Low retention
- Action
- Review today and schedule another review in 2 days.
Skill practice after repeated reviews
- Input
- 10 days since learning, 4 reviews
- Result
- Healthy retention
- Action
- Review in 3 days unless the topic is high stakes.
What to do next
If retention is low, review today. If it is still healthy, schedule the next review one to three days later.
Action playbook
- Review before retention drops below the point where relearning feels expensive.
- Shorten the interval for high-stakes knowledge.
- Use active recall instead of rereading when retention is low.
Common use cases
Plan exam review.
Schedule vocabulary practice.
Decide when to revisit a skill.
FAQ
Is this an exact result?
The tools provide practical estimates. Use them for planning, comparison, and prioritization.
Why does Decay.day group these tools together?
Each tool measures a form of value loss over time, then helps you decide what to refresh, fix, review, or retire.
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