Why do I consistently underestimate buffer times when planning with ADHD?
Many people with ADHD underestimate how long transitions or “buffer times” will take. This isn’t a motivation issue, it’s rooted in how ADHD affects time perception, planning and working memory. According to NICE guidance on ADHD, executive dysfunction affects the ability to sequence tasks and anticipate the steps needed between them.
Why time feels shorter than it is
Reviews on ADHD time perception suggest that dopamine dysregulation affects the brain’s internal timing processes, making time feel inconsistent or “slippery” (PubMed review). Working memory limitations also make it harder to track how long previous tasks or transitions actually took, so planning relies on guesswork rather than a reliable sense of duration.
This creates a pattern where buffers always seem unnecessary; until you run out of time.
The planning fallacy hits harder in ADHD
People with ADHD experience the common planning fallacy more intensely. Research links this to over-optimistic forecasting and “temporal discounting,” where immediate tasks feel more important than safeguarding time for what comes next. Emerging evidence suggests that the Default Mode Network plays a role in disrupting prospective time judgement.
As a result, transitions like packing away, switching tabs, or shifting mental sets often take longer than expected.
Why transitions are especially difficult
Studies on adult ADHD show that task-switching and time estimation become less accurate under unpredictability (PubMed task-switching study). In real life, that means:
- Forgetting the small steps between tasks
- Underestimating setup or cleanup time
- Struggling to disengage from the previous task
- Slow restarts after interruptions
NHS England’s ADHD Taskforce also highlights that time-management problems significantly affect work performance and productivity (NHS England report).
Evidence-backed ways to improve buffer accuracy
Strategies recommended across NHS, ACAS and CBT-informed approaches focus on externalising time instead of relying on internal perception:
- Use visible clocks, timers or countdowns to anchor transitions (ACAS guidance).
- Add 50–100% to your first estimate; the “double the buffer” rule supported by occupational therapy evidence.
- Create transition checklists (e.g., “close tabs, send follow-up, pack bag”).
- Chunk tasks into smaller steps so you can assign clearer timing.
- Use body doubling or shared task sessions for accountability, supported by emerging real-world ADHD research.
Workplace guidance such as ADHD UK’s adjustments also recommends predictable workflows and explicit planning supports.
If you’re exploring ADHD assessment or coaching
Some people seek structured support to help understand and manage executive difficulties. Private services such as ADHD Certify provide ADHD assessments for adults and children in the UK, alongside NHS pathways . Coaching or behavioural programmes can help you practise buffer-planning strategies in everyday routines.
Takeaway
Underestimating buffer times is a well-recognised part of ADHD, driven by time-perception differences and planning challenges, not lack of effort. By externalising time, inflating estimates deliberately and breaking transitions into clearer steps; planning becomes far more realistic and less stressful. This information is educational and not a substitute for personalised medical advice.
