I faced this problem. I am failed to be able to judge how much time does the follow project will takes. Sometimes I am able to complete a project in time by giving my extra effort, but I often miss the death line as with I get in trouble. Now I want to know how to judge the time project will take? As I am failed to calculate the time of project what it will take.

A good starting point is “twice as long as you think”. Make your best guess, then double it to get your new estimate.

You can improve the accuracy of your estimates by keeping track of your estimates and your actual completion times. If you usually underestimate the time for certain types of tasks, increase your estimates. If you usually overestimate the time for other types of tasks, decrease your estimates for those. This should eventually give you a fairly accurate “best guess”. Then double it, because it's always better to finish early than to finish late.

That’s the great piece of advice. I have seen similar advice on Blender Guru podcast he has mentioned this procedure which you have mention. Although I thought this advice was only applicable to blender as he is creator of blender tutorials. But based on your advice I believe it is applicable on any scenario thanks for that. @swiftcode ?. Will follow this procedure from now on.

@undefined In the future, I will keep better track of my efficiency so that I can provide better job completion dates. Currently, I am going to give more estimation time so that I can cope with it. Like if I can complete the project in 30 days then I will tell them it will take 45 days to complete the project.

A usuall estimate depends on your skills and experience. If you get experience, you get an idea of how long “you” will take to implement a certain feature. It is a good starting point to make a rough estimate of the features needed so you know how much time it may take per feature. Don't try to plan everything in high detail because it isn't worth it! Most of the time there are also unexpected issues which may come up so taking the feature time * 1.5 is a good idea to have some buffer.

What people often forget to estimate is testing their features. If you have a raw estimate of the entire project, finally apply another 1.5 factor to it to have enougth time for testing.

Sadly, most of the time people expect the results in quite shorter period than you gave them. This is an issue of our economy for trying to be time and money efficient but it nearly never works and the quality of the product suffers

**Most of the time there are also unexpected issues**
This it is quite common that unexpected issues occur due to which the projects lead to multple delays. Glad someone pointed out. Unfortunately you are right about the people believe that the project can be complete in short amount of time and sadly most folks are willing to do work on minimum time due to high competition.