First things first: You have to know where you’re going before you can plan how to get there. But peering into the future, then arranging your finances for a worry-free retirement is tricky. Circumstances are always changing:

• Your spouse gets a higher-paying new job with new benefits.

• Your investments do well (or don’t).

• The value of your house rises (or falls).

• Your company merges and the pension plan changes.

• College costs buffet your bank book.

• You go into business for yourself.

• Old Uncle Albert remembers you kindly in his will.

Factors like these can complicate planning for your retirement but shouldn’t deter you from beginning. To start building a realistic financial plan for retiring worry-free, start with five basic dynamics:

1. Where you stand now. That includes your personal savings, pension plans, investments and income prospects, as well as your debts and spending patterns.

2. How much money you’ll need to retire. We’ll help you tote that tab right here.

3. Where that money will come from. We’ll show you the range of possibilities and some typical case studies.

4. How much time remains until retirement. The strategy to achieve a worry-free retirement depends on the target date you’ve set and the progress you’ve made so far. Even fortysomethings who’ve procrastinated on their savings program have time to lay a solid foundation. You’ll find that it’s also possible to shoot for an early retirement with the right planning.

5. How much risk you are willing to take to help your nest egg grow. When it comes to investing retirement money, risk is a balancing act. Take too little and your nest egg may not grow as fast as you’d like. Take too much and you could find a crack in your nest egg that will be difficult to repair. The longer you are from retirement, the more risk you may be able to take; the shorter the time, the more risk you may need to take.