When it comes to investment gurus, Warren Buffett often finds himself at the top of the pecking order -- and for good reason. After having less than $10,000 in the bank in the mid-1950s, Buffett today sports a net worth of $73.4 billion, according to data from Forbes. Buffett's investment holding conglomerate Berkshire Hathaway (NYSE:BRK.A)(NYSE:BRK.B) has often outpaced the broad-based S&P 500 in terms of book value appreciation over the past 50 years.

What makes Buffett's claim to fame so interesting is that he isn't using any fancy methods to screen for the stocks he buys. Instead, he simply looks for well-run businesses with clear long-term competitive advantages that he can buy in Berkshire Hathaway's portfolio and sock away for years or decades. Some of the best examples include beverage giant Coca-Cola and banking behemoth Wells Fargo (NYSE:WFC), which have both been steady holdings for nearly three decades and are responsible for generating the hundreds of millions of dollars Berkshire pockets in dividend income each quarter.

Warren Buffett speaking with reporters.

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Buffett could be worth at least $100 billion right now

Yet, here's an arguably even more interesting stat: Buffett could very easily be the wealthiest man in the world right now -- a title that currently belongs to Microsoft's co-founder Bill Gates, who is worth just shy of $90 billion, per Forbes. If Buffett had simply chosen not to do one specific thing, his net worth would be $100 billion right now.

And, no, despite having criticized a younger Warren Buffett for not hanging onto his Disney shares back in the 1960s, the roughly $12 billion he's lost out on in future gains isn't what I'm talking about. 

Instead, the choice Buffett made a long time ago to become a philanthropist and donate a good chunk of his wealth to charitable foundations he believes in has diminished what could be the largest nest egg on the planet. In 2006, Buffett announced that he would begin gradually giving away his wealth to a network of his favorite charities, and over the past decade and change, he's contributed $27.54 billion. This includes a very recent donation of 18.6 million Class B shares of Berkshire Hathaway that were worth about $3.17 billion to five separate charities, including the Bill & Melinda Gates Foundation. Without this charitable giving, Buffett's net worth would be approximately $100 billion, if not higher, based on the appreciation in stocks over the past eight years.

A person writing the words "give back" in a book.

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Two significant advantages of charitable giving

However, we can't blame Buffett for being a philanthropist, since there are actually two significant benefits to giving.

To begin with, the charitable giving deduction tends to favor the wealthiest Americans. Donations made to eligible non-profit charitable organizations recognized by the Internal Revenue Service (IRS) allow an individual or couple to deduct a percentage of their donation against their taxable income. This percentage correlates with their highest marginal tax rate. Thus, wealthy individuals who find themselves in the uppermost tax bracket of 39.6% are allowed to deduct $0.396 for every $1 they donate to an eligible charity. By comparison, someone with a peak marginal tax rate of 15% (e.g., someone earning $30,000 a year) only receives a $0.15 deduction for every $1 donated.

It should be noted that even the wealthy can't deduct their way to $0 taxable income through charitable giving. The IRS limits deductions up to 50% of your adjusted gross income (AGI), with some special cases lowering the limit to just 20% or 30% of AGI. Nevertheless, it's a deduction that a number of wealthy Americans wisely take advantage of.

The second benefit of donating is that it allows Buffett, and anyone for that matter, to support and further a cause they believe in. For instance, donations to the Bill & Melinda Gates Foundation help fund access to healthcare and education, both within the U.S. and in developing countries.

A businessman holding two stacks of cash.

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Furthermore, it's not just individuals and couples that benefit from helping others. Businesses benefit, too. According to the 2015 Chronicle of Philanthropy's most charitable company list, the 20 most generous companies donated $3.5 billion in cash. Topping the list was Gilead Sciences (NASDAQ:GILD), which many of you may know as the drugmaker with the pricy once-daily hepatitis C pill. Gilead provided nearly $447 million in cash contributions in 2015, much of which given as grants for HIV/AIDS and liver disease research.

Wal-Mart (NYSE:WMT) came in second with $301 million in cash contributions, which included $100 million to advance economic mobility for retail workers, and an undisclosed amount to help the anti-hunger charity Feeding America distribute fresh produce.

Rounding out the top three is Wells Fargo with $281 million in cash contributions in 2015. According to Fortune, Wells Fargo aims to donate between 1.2% and 1.5% of its earnings each year. A portion of its donations go to the local communities where its banks operate, while the remainder is distributed on a more national level.

Though Warren Buffett may not be the richest man in the world as a result of his regular charitable contributions, he clearly is among the richest of heart.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.