Education
Study Efficiency Calculator
Score your learning effectiveness and predict knowledge retention after 1, 7, and 30 days using the Ebbinghaus forgetting curve.
Study Session Data
Enter your study session data to see efficiency score and retention predictions
How is this calculated?
Accuracy Rate = (Problems Correct / Problems Attempted) × 100%
Topics Per Hour = Topics Covered / Hours Studied
Efficiency Score = (Accuracy × 0.4) + (TopicsPerHour/5 × 0.3) + (Retention/10 × 0.3)
Ebbinghaus Forgetting Curve:
R(t) = e^(-t/S)
where R = retention, t = time (days), S = stability
S is derived from efficiency:
S = 1.5 × (efficiency / 100) + 0.5
Retention after 1 day = e^(-1/S) × 100%
Retention after 7 days = e^(-7/S) × 100%
Retention after 30 days = e^(-30/S) × 100%
Higher efficiency → slower forgetting → better long-term retentionFAQ
Frequently asked questions about study efficiency
What is the Ebbinghaus forgetting curve?
The Ebbinghaus forgetting curve shows how memory retention declines over time without review. After 1 day, you retain ~50%, after 7 days ~25%, and after 30 days ~15%. Spaced repetition dramatically improves these numbers.
How is study efficiency calculated?
Efficiency combines accuracy rate (problems correct / attempted), topics coverage per hour, and self-reported retention. A weighted average of these factors gives your efficiency score on a 0-100% scale.
What's a good study efficiency score?
Above 70% is good — you're retaining material effectively. 50-70% is average. Below 50% suggests your study methods need adjustment: try active recall, spaced repetition, or reducing session length.
How can I improve my retention after 30 days?
Use spaced repetition: review after 1 day, then 3 days, then 7, then 14, then 30. This can boost 30-day retention from 15% to 80%+. Active recall (testing yourself) is more effective than re-reading.
Does studying longer always help?
No. Research shows diminishing returns after 50-90 minutes of focused study. The Pomodoro technique (25 min work, 5 min break) maintains higher efficiency. Quality and method matter more than raw hours.
What's the ideal number of topics per session?
Research on interleaving suggests mixing 3-5 related topics per session is more effective than studying one topic intensively. However, new complex material benefits from focused single-topic sessions of 30-45 minutes.