Here's a very simple tool, just five questions to help you make a retirement projection.   Fidelity provides this on their website for anyone to use. 

You don't need to log in or have an account with Fidelity.  The tool does factor in some estimated Social Security income and uses Monte Carlo to simulate different market conditions.  However, it doesn't allow you to input pension or other projected income. I just tried it- very good starting point for calculating your "number".

Fidelity myPlan tool.

.