Have you ever started a task thinking it would take an hour, only to find yourself still at it three hours later? That common misjudgement is known as The Planning Fallacy — our tendency to underestimate how long things will take, even when we’ve done similar tasks before. This bias affects our productivity, our wellbeing, and our relationships, often leading to stress, overcommitment, and unmet expectations.
What Is the Planning Fallacy?
First identified by psychologists Daniel Kahneman and Amos Tversky in 1979, the planning fallacy describes our consistent failure to accurately predict how long tasks will take. This happens because we rely too much on our intentions and ideal scenarios (“the inside view”), and fail to consider how similar tasks have played out in the past (“the outside view”).
How It Shows Up in Daily Life
Work: Underestimating how long reports, meetings, or emails will take, leading to rushed deadlines or work bleeding into personal time.
Home: Assuming you can “quickly” paint a room or organise the garage, only to get stuck in unexpected complications.
Relationships: Expecting conflicts to resolve quickly, or underestimating the time needed for meaningful connection and emotional repair.
Even in quieter, slower-paced settings like a rural village, the planning fallacy persists. A simple trip to the post office might turn into a social detour, or a weekend garden task might be derailed by weather, missing tools, or unplanned conversations.
The Bigger Picture
The real cost of the planning fallacy isn’t just a few extra hours here and there — it’s what happens when those hours accumulate. Days become weeks, weeks become months, and suddenly years have passed with important goals still on the shelf.
We plan to read this book, start that project, take that trip, or make a change — but we continually misjudge how much time and space we need. Life gets filled with underestimated tasks and overcommitted calendars.
The result? A creeping sense that time is slipping by faster than we’re living it.
Recognising this helps us shift from reacting to time to consciously shaping it. Planning with greater realism isn’t just about better schedules — it’s about reclaiming the time to do what truly matters, before it quietly slips away.
You hear it in phrases like, "Where did the year go?" or "Time is flying."
You often feel like there’s “never enough time,” despite careful planning.
You’re frequently surprised by how long routine tasks take.
You commit to deadlines based on hope rather than past evidence.
You feel frustration or guilt when plans don’t go to schedule.
You catch yourself saying things like, “Where did the year go?” or “Time is flying.”
How to Recognise It
How to Work Around It
The planning fallacy isn’t a flaw in your character; it’s a common mental shortcut that affects how all human brains process time and complexity. But with awareness, reflection, and a few practical tools, you can learn to plan more realistically, reduce stress, and create space for what truly matters. Planning isn’t just about efficiency — it’s about aligning your time with your values.
Think about your week ahead — is there one task you keep underestimating? What would change if you gave it the time it actually needs??
