A few weeks ago a task was assigned to me by my Manager (in the field Software Engineering). I was given 2 days to discuss the scope of the changes and suggest a timeline for how long it would take for me to complete the task.

I grossly miscalculated the time it would take me to finish what was asked. Once the deadline approached I panicked and promised to finish it the very next. I pushed the deadlines twice this way and I am still far from finishing it.

My Manager is visibly disappointed and asked someone else to help me. This guy (who has more experience that I do) analysed what was remaining and has told me that it will be another 2 weeks minimum.

I have dug myself a hole here and am trying hard to get myself out of it. This Manager has joined my team a few months ago and I feel this incident is setting the absolute wrong idea about me in his mind.

How do I convey the message to my Manager that the task has been delayed because of the wrong estimate I gave and not for lack of trying? Anyone else doing that task would have taken as much time as it is taking at the moment.

I am planning to write an email to him explaining my fault in underestimating the scope of the task and overestimating my capabilities as a developer. But can this email be used as ammunition for proving that I am not capable enough? Should I just skip the written and talk to him face to face?

I would prefer an email because that would give me the time and space to express what I have to say clearly and will leave little scope to be misconstrued as anything else.

  • Just admit that you miscalculated the time needed, and express your disposition to do what you can to get this done asap (sometimes face to face is better, so you can even plan what to do with your manager). That doesn't mean you are an not capable as a developer. For future tasks, give more thought to the time estimation (some rule of thumb is to estimate the time and then say it will take twice that time, at least).
    – DarkCygnus
    Nov 30, 2017 at 17:32
  • I think a face to face talk is far better, but you are the only one who can tell if you can give all the information you want in a conversation or you would need an email for that Nov 30, 2017 at 17:35
  • 3
    Maybe writing some thoughts and phrases you want to say, and then say them face to face, so the words don't escape you when talking
    – DarkCygnus
    Nov 30, 2017 at 17:37
  • with respect, whatever picture your manager has of you in his mind, based of what you have told us, it is probably not "absolutely wrong". You miscalculated duration, and twice tried to take the easy way out hoping you could somehow magically finish it in time. You can resolve this, but from what I'm hearing, the picture doesn't look great.
    – ESR
    Dec 1, 2017 at 0:28
  • Every single software project, ever undertaken, has been massively overdue. Every. Single. One. It is utterly irrelevant whether you tell others now, later, or whatever. It is pointless now trying to "apologize" or whatever - just get on with the work.
    – Fattie
    Dec 1, 2017 at 14:37

3 Answers 3


That`s a slippery slope. You should have reported that you underestimated as soon as you became aware of it.

All i can suggest is emailing the manager as soon as possible with the request for a 1 on 1 and put task in agenda. With deadline discussion as addendum.

IMHO, longer you delay, more unprofessional it will look.

  • 1
    In addition to the to the @Strader's thought, keep your manager posted about the status/progress of remaining task so that your manager will have clear understanding that it is not about your performance but you really miscalculated the estimation... Dec 1, 2017 at 8:41

Short answer: Face to face.

At this point, you need to come clean as soon as possible. This communication should be done face to face. Once you meet, you can follow up on the results of your meeting via email if you feel the need.

Prior to the meeting, I would also have accurate information to present to your manager, and be fully prepared to be held to your new estimate.


Estimating development time is hard, that's why there are books on the subject. However, it appears to me that your big problem isn't estimation, it's lack of confidence and poor communication.

Now, it's tempting to think you can carefully craft an email that has exactly the right tone, and admits the minimum of fault. Then you can avoid a difficult conversation with your manager; the thing is, avoiding a difficult conversation with your manager is why you're in a mess now.

So, go face-to-face and don't overthink what you need to say. "Sorry, boss, I realize now I should have informed you as soon as I knew my initial estimate for X was well off" would be a good start. Have some better estimates available but don't ready a lot of excuses. Be prepared to listen.

It may seem tough tackling this head on but it's all in the anticipation. Do it once, and the next time it'll be easier.

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