How Much Training Do Employees Forget? What the Forgetting Curve Really Shows
August 2, 2026 · Research · 6 min read
Workplace learning does not disappear according to one universal timetable. There is no defensible rule that employees forget 50% of training after one hour, 70% after one day, or 90% after one week.
Those numbers are often attributed to Hermann Ebbinghaus, but his original experiments involved his own memory for nonsense syllables in the nineteenth century. They were important for establishing that memory weakens over time, but they do not provide a fixed retention percentage for modern workplace training.
What the forgetting curve actually tells us
The useful lesson from Ebbinghaus is not a universal percentage. It is that retention changes over time and is strongly affected by how material is learned, revisited and used.
Modern research supports two practical ideas particularly well:
- Spacing matters. Repeated learning opportunities separated in time generally produce better long-term retention than massed repetition.
- Retrieval matters. Asking people to recall and use knowledge strengthens later access to that knowledge more effectively than simply re-reading the same material.
A large quantitative review of distributed practice examined 839 assessments across 317 experiments and found that the spacing interval associated with best retention depends on how long the learner needs to retain the material.
Source: Cepeda et al., distributed practice review and quantitative synthesis.
What workplace data shows
The relevance of spacing is not limited to laboratory studies. A real-world analysis of workplace training data from 10,514 people found that the optimal spacing between retrieval events increased as the desired retention interval increased.
The study is important because it used naturally occurring workplace-learning data rather than assuming that laboratory forgetting percentages can simply be transferred to employees.
Source: Kang et al., The spacing effect stands up to big data.
So how much do employees forget after 30 days?
There is no single scientifically valid answer.
Retention after 30 days depends on variables such as:
- how well the material was understood initially;
- whether the content was meaningful and relevant to the employee’s work;
- whether the learner had to retrieve or apply the knowledge;
- how often the material was revisited;
- whether feedback was available;
- the complexity of the skill;
- the time between learning and later use.
That makes statements such as “employees retain only 8% to 12% after 30 days” misleading unless they refer to a specific study, population, learning task and test.
Why one-off workshops often underperform
A workshop can create useful understanding and practice, but a single event should not be expected to carry an entire behaviour-change strategy.
Learning is more likely to survive when organisations deliberately create opportunities to retrieve, practise and apply the material after formal instruction. Research on learning and memory has repeatedly shown that instructional decisions about spacing, retrieval and feedback can materially affect later retention.
Source: Pashler et al., Enhancing learning and retarding forgetting.
A practical reinforcement sequence after training
- End with retrieval, not another lecture. Ask participants to explain or demonstrate the core ideas before they leave.
- Return to the material after a delay. Use short questions, scenarios or tasks rather than simply resending slides.
- Connect learning to real work. Give managers and learners a specific behaviour or task to practise.
- Use feedback. Correct misunderstandings while the learner is applying the skill.
- Space later reviews. If knowledge must be retained for months, build later retrieval opportunities rather than concentrating all review in the first week.
What L&D teams should measure
Completion rates tell you whether people attended. They do not tell you whether knowledge survived or whether behaviour changed.
For important training, consider measuring:
- knowledge immediately after learning;
- knowledge again after a meaningful delay;
- ability to apply the skill in a scenario or real task;
- manager observation of target behaviours;
- operational indicators linked to the purpose of the training.
Build a reinforcement plan around the required retention period
A reinforcement schedule should reflect how long the knowledge or skill needs to remain available. There is no scientifically fixed “day 1, day 7, day 30” formula that fits every topic, but a practical sequence can deliberately revisit learning over increasing intervals.
| Point in time | Useful reinforcement | Purpose |
|---|---|---|
| End of training | Retrieval questions, demonstration or scenario | Check whether the learner can produce the knowledge without prompts |
| First few days | Short scenario, quiz or real-work task | Interrupt early forgetting and expose misunderstanding |
| One to two weeks | Applied task with feedback | Connect the learning to workplace performance |
| Several weeks later | Delayed retrieval or observed practice | Test whether learning remains accessible |
| Longer term | Periodic use in real work, refreshers where risk justifies them | Maintain capability over the period it is actually needed |
Reinforce knowledge and skills differently
Remembering a policy rule and performing a difficult conversation are different learning problems. Knowledge can often be checked with retrieval questions and scenarios. Skills usually require practice, observation and feedback. Complex judgement may require repeated exposure to varied situations rather than memorising one “correct” response.
A worked example: retaining a new escalation procedure
Assume a customer-service team learns a new escalation procedure. Instead of sending the slides again after 30 days, the organisation could:
- end the initial session with two realistic escalation decisions;
- send a short scenario a few days later;
- have supervisors observe one live or simulated case during the following week;
- review common errors after several weeks;
- measure whether escalations are becoming more accurate, not just whether employees opened the refresher.
Common reinforcement mistakes
- resending the same presentation and calling it spaced learning;
- testing recognition only when the job requires unaided recall;
- reinforcing trivia instead of job-critical decisions;
- using identical questions so learners memorise the quiz rather than the skill;
- ignoring manager support and opportunities to apply the learning.
For the wider question of whether learning time translates into performance, see Training Time vs Performance.
Retrieval + spacing
Practice + feedback
Varied scenarios + reflection
Design reinforcement around the consequence of forgetting
Not every piece of training content deserves the same reinforcement effort. Start by identifying what learners must recall without assistance, what can be supported by a job aid and what requires repeated practice because an incorrect decision carries meaningful risk.
Critical emergency actions, safety decisions or high-risk compliance judgement may justify repeated retrieval and scenario practice. Reference information that changes frequently may be better supported through an accessible tool than memorised. This distinction reduces unnecessary refresher activity while concentrating practice where forgetting matters.
Diagnose forgetting before prescribing another course
When performance deteriorates after training, first determine what actually failed. The learner may not remember the information, may remember it but lack fluency, may understand it but face a process barrier, or may be receiving conflicting signals from managers and systems.
Use delayed questions, observed tasks, scenario decisions and manager feedback to distinguish these problems. If knowledge is missing, retrieval practice may help. If the skill is weak, add guided practice. If the workplace blocks use of the skill, redesigning the process or management support may matter more than another learning event.
Build reinforcement into normal work
Reinforcement can be built into normal work rather than treated as a separate training activity. Team reviews, supervisor observation, checklists, peer discussion, quality audits and real-work assignments can all create retrieval and practice. Integrating reinforcement into the work system reduces reliance on periodic refresher courses and makes learning easier to sustain.
Design training for retention, not attendance
The forgetting curve is useful when it reminds organisations that learning needs reinforcement. It becomes unhelpful when it is turned into a universal set of percentages that the evidence does not support.
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