Many people dream of retiring early, or at least on time. But if you kick off that milestone unprepared, you'll regret pulling the trigger. And while delaying retirement may not be something you want to do, it's something you'll have to do if these three scenarios apply to you.

1. You're short on savings

You need independent savings to live comfortably in retirement for one big reason: Social Security will only replace about 40% of the income you're used to, and that assumes you're an average earner. If you're an above-average earner, it will replace even less. Meanwhile, most seniors need 70% to 80% of their former paycheck to enjoy life and keep up with their bills, and retirement savings are generally what's needed to fill in that gap.

Older man looking at stacks of paperwork while holding his head


As a general rule of thumb, it's wise to enter retirement with about 10 times your ending salary socked away in an IRA or 401(k). If your current savings balance looks nothing like that, then you'll need to look at postponing retirement until you're able to get closer.

Say you're 65 years old and are itching to retire, but you currently earn $75,000 a year and only have $500,000 socked away. Though half a million dollars is certainly a respectable sum, it means you're still worlds away from the $750,000 should you be targeting. If that's the case, postponing retirement until age 70 will give you five more years to build wealth. And if you max out a 401(k) at today's annual limit for older workers -- $26,000 -- for five years, you'll wind up with a bit more than $750,000 if your investments in that account generate a relatively conservative 5% average annual return during that time.

2. You're saddled with debt

Once you retire and move over to a fixed income, you may find that you're forced to cut back on certain expenses just to make ends meet. It therefore stands to reason that entering retirement with debt payments that monopolize your limited income is not a good thing to do at all.

If you're carrying debt, it pays to eliminate it before you retire, and you can do so by cutting back on expenses in your current budget or getting a second job to boost your earnings. This especially holds true if you're carrying credit card debt, which is generally considered the least healthy kind to have.

That said, if the only type of debt you have is mortgage debt, you don't necessarily need to postpone retirement until your home is paid off. Mortgage debt is regarded as one of the healthiest types of debt out there, and the interest you pay on your home loan can serve as a lucrative tax break.

3. You have no idea what you'll do with your time

Retirees are 40% more likely than workers to suffer from depression. The reason? They often find themselves hopelessly bored once they stop having a job to go to.

If you have no idea how you'll spend your days in retirement, then you're better off continuing to work until you figure it out. And if you know what you want to do with your time but can't afford it (say, you're hoping to travel extensively), work a few more years and boost your savings to make your goals more attainable. If you decide to retire without having a good sense of how you'll fill your days, you may find that your mental and physical health quickly start to deteriorate.

Postponing retirement may seem like a terrible thing to have to do, but remember, Americans are living longer these days, and if you push yourself to work until your late 60s or early 70s, there's a good chance you'll still enjoy a solid 20 years of retirement, if not more. And that way, you'll retire at a time when you're financially and emotionally ready.