You need retirement savings to live comfortably as a senior. That may seem like the sort of advice you'd acknowledge by rolling your eyes and offering up a nod of appeasement, but here's the deal: Once you retire, you'll generally need a good 70% to 80% of your former paycheck to pay your bills and continue living the way you want to.

Social Security, if we're lucky and benefits aren't slashed in the future, will replace about 40% of the income you're used to living on, assuming you're an average earner. This means that if you retire on Social Security alone, you'll be short 30% to 40% of your former wages. And at that point, you'll need to make some serious lifestyle compromises -- something most people hate doing, in general, but especially when they're older.

So let's get back to our initial point: You need retirement savings to fund your senior years. There's no getting around it. But new data from Willis Towers Watson tells us that 70% of workers today are saving less for retirement than they think they should.

Man at laptop with serious expression


Clearly, that's a problem. If you're in that boat, it's imperative that you start making changes -- before you find yourself in a sorry financial state later in life.

How much retirement savings is enough?

There's no magic number that guarantees you'll manage to pay your bills and enjoy life as you want to in retirement. But a general rule of thumb is to save 10 times your ending salary. If you're only in your 30s or 40s, you may not have a sense of what that is. But there are other milestones you can aim for along the way.

Investment giant Fidelity advises to have the equivalent of your current salary in retirement savings by age 30, three times your salary by age 40, and six times your salary by age 50. Therefore, if you're 42 years old earning $80,000 a year and your IRA or 401(k) balance is hovering around $25,000, you've got work to do.

The good news? If you're behind on savings today, a few simple moves on your part could help you ramp up.

First, get yourself on a budget. It may seem boring or unnecessary, but once you get in the habit of following a budget, you'll have a much better sense of where your money goes month after month. From there, you can identify expenses to cut back on.

For example, you may not realize you spend $400 a month at restaurants yet lack retirement savings in a very big way. If you were to slash that restaurant spending in half and bank an extra $200 a month in your IRA or 401(k) for the next 20 years, all the while investing that money at an average yearly 7% return, which is just below the stock market's average, you'd pad your savings by roughly $100,000.

Another option? Look at getting a second job and use your earnings from it to fund your nest egg. If you go that route, you may be in a position to build solid savings without having to cut back on spending at all.

The fact that most Americans acknowledge their retirement savings shortcomings is one part troubling and another part encouraging. By owning up to the fact that they could be doing better, workers today may be more apt to make changes that help their savings balances improve.

If you're behind on savings, it pays to do the same. That way, you won't end up kicking yourself when your senior years roll around and you're horrendously short on money.