Starting to save for retirement, a few decades late

If only saving for retirement worked in nicely planned, easily mapped steps. You make a certain amount of money, put away 15 percent of it toward retirement saving each year, then get a raise, put a little more away -- into the company 401(k) plan with a match from your employer. And poof! By 70 you're ready to retire financially secure.

Life is not a spreadsheet

But we all know life rarely works that way, and sometimes the money just isn't there. Many people have student loans to pay down or a sudden expense, like having a baby. 

And for some it isn't even top of mind to begin saving for retirement early. The Institute for Company Investing dug through the Federal Reserve's consumer finance survey data and found among young people age 21 to 29, just 13 percent said retirement was their primary reason for saving. For people in their 50s, 43 percent said it was their main focus for saving.

Even in employer-sponsored 401(k) plans, which only half of Americans working in the private sector have access to, the typical balance is just over $100,000, according to the National Institute on Retirement Security. That may seem like a lot, but it's only a $400 per month cushion in retirement. And even if you factor in Social Security benefits, it may not be enough to cover major expenses like medical bills.

So what can you do?

Don't ostrich: Figure out how much you'll need -- as early as you can

The sooner you understand how much you'll need to save, the better off you'll be at making decisions that help meet that goal. Keep in mind: Many people think they'll be able to work later in life than actually are able to do so (often because of health reasons).

Most financial experts recommend being conservative in your estimates of how long you'll be able to work and what you can realistically plan as a retirement income (whether it's 75 percent or more of your preretirement salary). Depending on when you retire and begin taking Social Security, you may need to have saved as much as 10 times your preretirement income.

The US does have a government retirement plan, Social Security, which you contribute to with every paycheck. If you're just getting started, check out Social Security's website and calculate what benefits you can expect when you retire. Just put in your wages and expected retirement date.

Remember: The later you retire, the higher your monthly Social Security benefit will be. So if you can retire at 70 rather than 64, you'll increase the amount you receive.

Once you know what you can expect in Social Security benefits, check a retirement calculator or speak with a financial adviser to find out the "gap" between your expected Social Security check and what you think you'll need in retirement. This is the number you should aim for when you begin saving a portion of your income.

Saving and investing

Compound interest is your friend -- we hear it time and time again, so if you can start saving earlier, your portfolio will have more chance to recover from market shocks and also earn more in interest. If your money is in a retirement account like an IRA or 401(k), those earnings accrue tax-free. In a Roth IRA, the money you put in is taxed upfront, so any earned income accrues tax-free and will also be tax-free when you take distributions after age 59½.

Make a budget and figure out what spending is essential and what isn't. Most financial experts recommend saving about 15 percent of your income for retirement (including any company matches) beginning in your 20s. But if you're older, that portion of your income may need to be higher. 

"A lot of people start later in life -- people can be successful, but they have to put away more money because they're playing catch-up," Daniel Keady, TIAA's chief financial strategist told CBS MoneyWatch. "We often talk about maybe 10 percent to 15 percent, but depending on your age you may need to put away even more." 

Right off the bat, aim to cut your monthly spending by 10 percent and put that into your retirement savings. Sure, you could start with that $6 morning latte habit, but you can also find big savings opportunities in major personal expenses like telecom bills, insurance premiums and subscription services.

If possible, add an income stream and prioritize contributing that money to retirement accounts. Can you take on a part-time job or rent out a room until your retirement is back on track?

Depending on your age, take advantage of catch-up contributions that may be available to you. For instance, if you're over 50, you can contribute up to $24,000 to your 401(k) this year instead of just $18,000 if you're under 50.