The age you begin taking Social Security will affect your monthly income for the rest of your life, so it's a decision to be made carefully -- especially if you're going to be relying heavily on your benefits in retirement.

The right age to claim will differ from person to person, as it depends largely on your unique circumstances. That said, it can sometimes be helpful to see what the research says about when to file.

In one comprehensive study, researchers studied retirees' claiming decisions to determine the "optimal" age to begin claiming. Here's what the data has to say about the best and worst ages to start taking Social Security.

How age affects your benefits

First, it's important to understand exactly how the age you file for benefits will affect your monthly payments.

To receive the full benefit you're entitled to based on your work history, you'll need to file at your full retirement age (FRA). This age varies by birth year, but it's 67 years old for everyone born in 1960 or later.

Social Security full retirement age chart.

Image source: The Motley Fool.

By filing as early as possible, at age 62, your benefits will be reduced by up to 30%. You can also delay claiming past your FRA, and by waiting until age 70 to file, you'll receive your full benefit amount plus a bonus of at least 24% per month.

These adjustments are permanent, too. In general, once you begin claiming, your benefit amount is locked in for life (save for annual cost-of-living adjustments). It's crucial, then, to ensure you're making the best possible decision about when to file for Social Security.

The clear winner (and losers)

In a 2019 study, researchers at United Income examined the claiming decisions of retirees, then looked at those retirees' income throughout the rest of their lives. From there, they used that data to determine how many retirees made the optimal choice to maximize their lifetime income.

The clear winner? Age 70. Researchers found that although it's the least popular time to file (with only 4% of retirees filing at that age), around 57% of the study participants could have earned more over a lifetime by waiting until age 70 to claim.

Claiming prior to age 64 was the least optimal age to file, according to the data, as only 6.5% of retirees would maximize their lifetime income by filing at ages 62 or 63.

Filing at the optimal age makes an enormous difference, too. The researchers found that by claiming Social Security at the less-than-ideal age, the average retired household will miss out on around $111,000 in total income over a lifetime.

What's the best age for you?

Again, there's no single correct age for all retirees to file, as it will depend on your situation. But by considering your priorities in retirement, it can make this decision a little easier.

If your main goal is to maximize your monthly income, delaying as long as possible (ideally until age 70) may be your best bet. The average retiree collects around $739 more per month at age 70 than at age 62, according to the Social Security Administration's most recent data released in December 2023. If money is tight in retirement, those larger checks can go a long way.

On the other hand, if retiring earlier is a bigger priority than maximizing your income, claiming early can be a smart move. Money isn't everything, and if you have a strong retirement fund or are willing to make financial sacrifices to retire in your early 60s, claiming early can make it easier to achieve that goal.

Also, it can be smart to take your health into consideration. While it's not the most pleasant topic to think about, if you have reason to believe you may not live well into your 70s or later, it could be a good idea to claim early. You'll still collect smaller payments each month, but you might receive more in total than if you were to delay claiming.

Delaying Social Security until age 70 can be a smart financial move, but finances are only one part of the equation. By looking at the big picture and considering your priorities in retirement, it will be easier to decide on the best age for you.