Retirement is an exciting milestone in life, and most people can't wait until they can finally leave their jobs for good and have the opportunity to live a life of leisure.

But before you retire, there are plenty of questions you should be asking yourself to ensure you're ready for this next stage in life. The last thing you want is to retire before you're ready and end up regretting your decision, so the more prepared you are, the happier you'll be.

Before retirement is on the horizon, ask yourself these three important questions to make sure you're on the right path.

Man with question marks above his head

Image source: Getty Images

1. How much of your savings can you withdraw each year?

It can be tough to determine how much you need to save by retirement age, but if you leave your job and then your savings run dry after five or 10 years and you can't return to work, you may be out of luck. So long before you even consider retiring, make sure you know how much you can withdraw from your savings so that your money lasts the rest of your life.

One of the easiest ways to do this is to use the 4% rule, which is a guideline stating that if you withdraw 4% of your total savings during the first year of retirement and then adjust your withdrawals each subsequent year to account for inflation, your savings should last around 30 years. So if you expect to have, say, $500,000 saved by the time you retire, that means you can withdraw $20,000 the first year of retirement.

If that's not enough to live on, you'll need to work to save more before you retire. To figure out what, exactly, you should aim to save, you can work backwards by multiplying the amount you need each year by 25. So, for instance, if you expect to need around $40,000 per year in retirement, multiply that figure by 25 to get a result of $1 million. Then to check your work, take 4% of $1 million for an answer of $40,000.

If you're experiencing some sticker shock at just how expensive retirement is, just remember that the harder you work now to at least get near your saving goal, the more enjoyable retirement will be. And the earlier you calculate how far your savings will go and whether you're on track, the easier it is to make adjustments if necessary.

2. How much will you be receiving in Social Security benefits?

Fortunately, if your savings aren't quite where you want them to be, you'll have Social Security benefits as another source of income in retirement. But your benefits are designed to replace only around 40% of your income, so you shouldn't be relying on them as your primary income source.

To figure out how much money will need to come from your personal savings to pay the bills in retirement, you'll first need to determine what you'll be receiving in Social Security benefits. For the most accurate estimate, you can check your statements online by creating a mySocialSecurity account. This will give you a personalized estimate based on your earnings record. Or for a rough idea of what you'll be receiving in benefits, you can also use the Social Security Administration's online calculator.

Keep in mind that the amount you actually receive will depend on what age you claim. The only way to receive your full benefit amount is to claim at your full retirement age (FRA), and if you claim earlier (as early as age 62) or later (up to age 70), you'll receive either a reduction or increase in benefits.

So, for example, let's say your FRA is 67 years old, and you've determined that if you claim at that age, you'd be eligible to receive $1,500 per month (or $18,000 per year) in benefits. You expect to need around $40,000 per year in retirement, so by subtracting the $18,000 per year you'll be receiving in benefits, that means $22,000 per year will need to come from your personal savings. However, if you'd instead claimed benefits at age 62, your checks would be reduced by 30% -- leaving you with just $1,050 per month, or $12,600 per year. In that case, assuming you'd still need $40,000 per year to get by, you'd need to come up with $27,400 from your own savings each year.

3. How will you cover healthcare costs?

Roughly nine in 10 Americans are either already relying on Medicare or plan to rely on Medicare for their healthcare needs in retirement, a survey from the Nationwide Retirement Institute found, and yet three-quarters of older adults don't understand exactly how the program works.

If you aren't certain about what you'll be paying for health insurance or what costs you're responsible for in retirement, healthcare expenses can quickly drain your retirement fund. Even with Medicare coverage, you'll still need to pay for all premiums, deductibles, coinsurance, and copayments. In addition, Original Medicare (or Parts A and B) doesn't cover most routine care or prescription drug coverage, so those are other out-of-pocket expenses you may be responsible for. You can instead enroll in a Medicare Advantage plan that provides greater coverage, but you may face higher premiums each month.

It's tough (if not impossible) to predict what types of healthcare costs will pop up during retirement, but if you go into retirement assuming these expenses will be fully covered by insurance, you'll be in for an expensive surprise. Make sure you have a rough idea of what costs you'll be responsible for, and then account for these expenses in your retirement plan. For example, you may set aside a certain amount each month in a health savings account, which provides tax benefits when used for medical expenses. Or you may enroll in long-term care insurance to prepare for the skyrocketing costs of nursing home care (which is another expense Medicare won't cover).

Preparing for retirement isn't easy, but the best way to ensure you're ready to retire is to do as much research as possible. The more you know about what retirement will cost and how you'll cover those costs, the more enjoyable and less stressful your golden years will be.