Hi Lea great question. The best way to ensure if you are saving enough for retirement would be to sit with a Certified Financial Planner and have a plan designed that focuses on retirement planning.
If you work for a firm that offers a 401(k) plan or some form of retirement plan. The retirement plan provider might have some basic tools to help with this question.
There are also many great online tools from companies such as Vanguard, Schwab, and Fidelity. Some of the new "Robo Advisor Firms" such as Betterment and Wealthfront have some tools. You can also check out Personal Capital.