Do you know your net worth? To retire early, you need financial stability and a clear idea of what your standard of living will be.

©iStockphoto/Jacqueline Perez

Financial Planning

The first step when planning for an early retirement is to figure out exactly how much money you have right now. This is called your net worth. Net worth is calculated by adding up all of your assets (cash, stocks, retirement accounts and the value of your home) and subtracting all of your outstanding debt (mortgage, student loans and credit card debt).

When you know how much you have, you need to figure out how much money you'll need when you retire. This amount depends on several factors: what you want to do when you retire, how early you want to retire and what standard of living you want to enjoy when retired.

If you want to keep up your current standard of living as a retiree, the rule of thumb is that you'll be spending monthly at least 80 percent of what you're spending now [source: MSN]. That other 20 percent you won't be spending accounts for work-related expenses: gas or public transportation fares for your commute, dry cleaning bills, lunches and the like. But if you plan to travel, play more golf or fix up a classic car as a retiree, you'll quickly make up that 20 percent you thought you were saving by not working.

Perhaps the most important factor when calculating how much you'll need is how early you want to retire. There's a big difference in planning for a 20-year retirement and a 40-year retirement. Plus, the earlier you retire, the longer you'll have to wait to get Social Security benefits. This isn't a problem for people who retire after the minimum age for collecting Social Security (currently 62). But if you retire too early, you might not have enough to get by on until Social Security kicks in.

Another serious consideration when planning for an early retirement is health insurance. When you're employed, you pay part of your monthly insurance premium and your employer pays the rest. When you retire, you're guaranteed coverage under the same insurance policy for the next 18 to 36 months through the Consolidated Omnibus Budget Reconstruction Act, also known as COBRA. COBRA is meant as a temporary protection for employees who lose or change jobs. But even with COBRA, you'll be paying the full premium, including what your boss used to pay.

You're not eligible for Medicare benefits until you're 65 [source: MSN]. So, until you reach that age, you'll need a supplementary insurance policy. When you apply for a new policy after COBRA runs out, you might be surprised at how expensive it is to insure a 60-year-old with pre-existing medical conditions. The cheapest policy for a 62-year-old nonsmoker is $300 a month, and it increases if you smoke, have a history of heart problems, high blood pressure, diabetes and other conditions [source: MSN].

One way to get started on your early retirement budget is to use one of the many free online retirement calculators to figure out how much you'll need in net worth to retire at a certain age. But the only way to know if your planned retirement spending will work is to try a dry run [source: Kiplinger]. Try to live for three months on the projected monthly amount that you hope to live on when retired. If it's not working now, it certainly won't work when you factor in increased healthcare and insurance costs.

How can you start saving for an early retirement now? What are the best long-term investments for building up a retirement nest egg? Keep reading.