Estimating the effort, time, and resources needed to complete project activities is one of the most challenging tasks that project managers must face. This is because of the inherent uncertainty associated with many activities. Almost all the projects are unique. Uncertainty because the activity is unique to the project or the activity is being accomplished by a resource that is not a practiced expert or the interaction of this activity with other project activities is unique in this project. All of these can create problems when estimating effort, time or resources. If the effort needed to complete the scope is uncertain - for instance the number of hours of work needed to complete an analysis - the time and resources needed will be uncertain. There are various tools which are mainly used for estimating project activities. This document briefly describes about the tools and techniques for estimation along with the examples. Before the project work begins, you must make sure that the work is properly understood and agreed to by the project sponsor and key stakeholders. You need to work with the sponsor and stakeholders to ensure that there is a common perception of what the project will deliver, when it will be complete, what it will cost, who will do the work, how the work will be done, and what the benefits will be. The larger the project, the more important it is that this information be mapped out formally and explicitly. All projects should start with this type of upfront planning to prevent problems caused by differing viewpoints on the basic terms of the project. You should create an overall project work plan before the project starts. This helps you estimate the total project effort and duration. Without proper project planning, there will be poor estimates, poor scope control and lack of business support. Project managers must use some effective project planning tools in order to make sure the project flow is maintained. This document explains about the tools for planning along with some instances. Along with the tools and techniques of Planning and Estimation, this document shows the importance of BA Tool which is a software created for effective planning and estimation.