Why Are We Bad at Estimating How Long Tasks Take?

2 Methods on How to Get Better at Estimating Time

Hi friend!

This week I want to talk about why we’re bad at estimating how a task will take us and how we can get better at it (especially if we’re doing something for the first time).

Why should you care? Getting better at estimating how long tasks and projects take means you’ll:

  • Stop overscheduling your days

  • Avoid the stress of unrealistic deadlines

  • Avoid disappointing others by needing to push back on promises you have made

Unfortunately, many people don’t slow down and reflect on their experiences to realise the mental, emotional and professional cost of being a bad at estimating time.

But once you understand why it happens and how to get better at estimating time for tasks and projects, then you’ll really experience a calmer and less stressful approach to working and being productive while hitting your goals.

Let’s dive in!

Why are we bad at estimating how long tasks will take us?

In order to achieve your goals without the feeling stressed and like you’re constantly hitting up against a deadline, you first need to understand why humans are bad time estimators:

1. Planning Fallacy

Psychologists Daniel Kahneman and Amos Tversky uncovered this concept in their research.

Humans have a tendency to underestimate the time needed to complete a task and the costs and risks related to that task. This leads us to make poor planning decisions and underestimating how long things actually take us to do.

2. Optimism Bias

Humans are generally bias towards being positive and optimistic about the world and our abilities.

A very important trait for our human race to keep on surviving! When we plan, we overestimate how smoothly things will go and plan for the best case scenarios.

Rather than being realistic and building in contingencies for the worst case scenario.

3. Harder it gets, more distracted we get

From personal experience, when a task or project gets hard, we can get easily distracted as fatigue sets in and willpower diminishes.

This is especially true when we’re learning a new skill or doing a task for the first time. This leads to tasks taking longer than expected.

4. No experience guiding our estimations

When we have no previous experience of doing the task, we have nothing to guide us on making the time estimate. So we tend towards an optimistic time estimation when scheduling and planning our tasks and days.

Does any of this sound familiar to you?

Not all is lost, here are two methods I’ve used that helps me to get better at estimating time:

Add extra time by using a multiplier

Adding extra time is the simplest method for overcoming our frequent underestimation of how long tasks actually takes to do.

A quick and dirty way to do this when you’re trying to estimate how long a new task will take you (especially if it involves learning or using new skill), is to simply to add extra time by using a multiplier.

I recently experienced planning fallacy and optimism bias when I was creating video lessons for my Notion mini-course that I’m currently working on. It was the first time I creating a video lesson. And I severally underestimated that it would only take me a few hours to create my first 10 minute video lesson.

It took 5x longer than my estimate!

When I created my second video lesson, I gave myself significantly more time (learning from my experience).

But I was pleasantly surprised that it took me around 3+ hours to make the 9 minute video lesson from beginning to all the way to the end where it was uploaded onto Youtube and embedded into my Notion lesson page.

That process would have been even faster had I documented certain steps or settings I used when I created my first video lesson. So that I didn’t have to look up those steps or settings again when recording the second lesson.

❗️ Bonus tip: if you do something 3 times or more, it’s time to write a Standard Operating Procedure. It will make the process much more efficient the next time you’re doing that task!

⚡ Takeaway Steps:

  • Write down how long you think something will take and then write down how long it actually took.

  • For example: Original estimate = 30 minutes ; Actual time it took = 2.5 hours ; 5x is your multiplier

  • This becomes your multiplier number that you can use for estimating the time required for tasks in the future. It’s a great starting point.

  • If you finish the task earlier than expected, go do something fun or relaxing with the “Extra” new found time!

Break down the task into specific actions & add a time estimate for each action

Often one task turns out to be 10 different tasks!

So in fact that one task is actually a project in it’s own right. To help us identify if that one task is actually one task or a project, do a brain dump of all the actions and the time estimate for each action associated with this “one task”.

Lets use my video lesson creation task from above as an example.

My task was to create a video lesson for my Notion mini-course. If I was to brain dump the actions related to this task, here are just a few actions that I would have written down:

  • Write the lesson script (3 hours)

  • Record the screen capture (2 hours)

  • Look for a video editing software (1 hour)

  • Learn how to use the video editing software (1 hour)

  • Learn how to use the software to record voice overs (1 hour)

  • Research what software to use to record voice overs (1 hour)

  • Learn how to use the software to record video screen capture (1 hour)

  • Research what software to use to record a video screen capture (1 hour)

  • etc.

That’s just the tip of the iceberg of actions I needed to take to do the task “record a video lesson”!

If I had remembered to do a brain dump of all the actions, with the estimated times next to each action, I would have realised how much I had to learn and do. Then I could have planned for significantly more time to do this.

I would not set myself unrealistic deadlines and then feel stressed or bad about delaying the launch of my Notion mini-course.

❗️ Bonus tip: If the task is really important, make sure to time block it into your weekly schedule so that you’re consciously setting aside time for that task.

Takeaway Steps:

  • Break down a task by brain dumping all the actions and time required for each action.

  • If there are no actions that you can think of, congratulations! It means your task is actually the smaller possible unit to take action on.

  • If there are multiple actions, reconsider how much time you set aside to do that task, and whether the task is actually a project in its own right.

In Case You Missed It On Social

I shared one of my favourite Notion tips. I use this all the time to organise ideas and information quickly!

A weekly roundup of interesting and relevant resources in the realm of Slow Productivity and Notion systems to help you find time to cultivate your passions beyond work.

  1. My essays on Cal Newport's 4 Advanced Time-Block Planning Tips For Part-Time Solopreneurs With A Day Job (Even If You’re a Veteran Time-Blocker)

    Cal Newport says he’s an aggressive time blocker. But he only timeblocks his working hours and he finishes no later than 5 to 6pm each day. This allows his to wear 7 different hats in his life. Check out the 2 part essay for how Cal does it.

    → Read the 2 part essay series: Part 1 and Part 2

  2. Perfectly Confident: How to Calibrate Your Decisions Wisely by Don A. Moore

    I read this book a few years ago. It’s about the importance of confidence, but also how over confidence can hinder growth. So if you’re curious to learn the psychology behind human confidence, how over confidence occurs (which contributes to our tendency to under-estimate time) and how to have just the right amount of confidence.

    Read the book

  3. Ditch Your To-Do List and Do This Instead with Sam Corcos on The Tim Ferris Show

    Sam Corcos shares how he manages his calendar, tasks and emails. Very insightful to hear how a CEO keeps 25 to 50% of his working days “free” from obligations to avoid overscheduling himself and make space for when things take longer. He even has a tip on how to get better at time estimations!

    Watch the interview clip

That’s it!

Thanks for reading.

Hit reply and let me know what if you struggle with estimating how long tasks take—I’d love to hear from you!

See you next week,


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