It's hard to imagine a billionaire selling sandwiches, flipping burgers or stocking shelves, but many of the world's wealthiest people actually came from very humble beginnings. They might be flying in private jets and running successful companies now, but billionaires like Warren Buffett, Richard Branson and Elon Musk each built their success from the ground up.
Click through to find out what these 15 famous billionaires did to nab their first paychecks — and learn what they did to become and stay billionaires.
- Net worth: $7.3 billion
- First job: Mailroom clerk, 1964
- Salary then: $1.60 per hour
- That salary today: $12.64 per hour
Billionaire entertainment mogul David Geffen got his start in the mailroom of talent agency William Morris. Geffen learned to steam open the mail and read memos on desks upside down — according to a New Yorker interview with agency president Dave Wirtschafter — which helped him figure out how he could be more valuable to the company.
He later went on to found Asylum Records, Geffen Records and DreamWorks SKG.
- Net worth: $6.6 billion
- First job: Photographer's assistant, 1957
- Salary then: $1.38 per hour
- That salary today: $12 per hour
Well before his signature power suits changed the fashion world, Giorgio Armani served in the Italian military. It was during this time he got interested in fashion.
"I was doing my military service and I had 20 days off on vacation in Milan," he told Time magazine in 2009. A friend asked if he wanted to earn some extra money helping a photographer at a department store and a future fashion icon was born. Once Armani's required military service was completed, he went to work at La Rinascente, a well-known department store in Milan, where his design career started.
- Net worth: $6.3 billion
- First job: Door-to-door sales, 1998
- Salary then: $10.26 per hour
- That salary today: $15.36 per hour
Uber founder and former CEO Travis Kalanick's first job was in door-to-door sales, selling knives for Cutco as a teen. His entrepreneurial spirit blossomed and at age 18 he started his first business, an SAT-prep course called New Way Academy.
Kalanick studied computer engineering at UCLA but dropped out in 1998 to work in the startup world. The risk paid off — Uber is valued at $69 billion and operates in about 600 cities around the world.
- Net worth: $4 billion
- First job: Red Bull promoter, 2008
- Salary then: $385 per month
- That salary today: $438 per month
When Snapchat founder Evan Spiegel was still in high school at Santa Monica's exclusive Crossroads school, he interned for Red Bull promoting the energy drink in bars and clubs. After he graduated from high school, Spiegel went on to study product design at Stanford, where he met his future Snapchat cofounders Reggie Brown and Bobby Murphy.
- Net worth: $2.4 billion
- First job: Sandwich maker
- Salary then: N/A
Los Angeles Chargers owner Alex Spanos started his road to billions in 1951, when he borrowed $800 to buy a truck to sell sandwiches to migrant workers in the San Joaquin Valley. Spanos and his wife made sandwiches at night so he could drive around selling them the next day.
Just five years later, Spanos was a millionaire and actively investing in real estate. In 1982 he bought part of the then-San Diego Chargers and spent the next 10 years slowly buying ownership of the entire team, which is now worth more than $2 billion.
- Net worth: $2.3 billion
- First job:Ad executive, 1960
- Salary then:$6,541 per year
- That salary today: $54,095 per year
CNN founder-turned-philanthropist had dreams of joining the Navy, but fate had another plan. After being kicked out of Brown University for having a woman in his dorm room, Ted Turner began working for his father's advertising agency.
He showed natural talent for the business and more than doubled the office's revenue during his first year of employment. Turner eventually took over the business, which he sold to Time Warner for $7.5 billion in 1996.
- Net worth: $1.6 billion
- First job: Race car driver, 1962
- Salary then: N/A
Before he started his transportation services company, Roger Penske was a race car driver. As a young entrepreneur, Penske bought, raced and sold race cars until a fateful decision changed his life.
"I was asked to take a driver's test to race in the Indianapolis 500 around 1965, and I couldn't do that because I had a job, and I had to pass on it," Penske told Automotive News, Instead. "Mario Andretti took his test and became one of the greatest race car drivers of all time." Penske might not have lived out his racing dreams, but with a net worth of $1.6 billion, it looks like he managed to fare pretty well.
- Net worth: $1.3 billion
- First job: Software engineer, 1991
- Salary then:$44,971 per year
- That salary today: $80,825 per year
It might come as no surprise that Twitter founder Jack Dorsey's first job was in computer software. When he was still a high school student in St. Louis, the tech giant became fascinated with computer programming — especially managing fleets of taxi cabs and delivery vehicles. At just 15 years old, Dorsey wrote dispatch software that is still used by some taxicab companies today.
- Net worth: $1.2 billion
- First job: Stockroom associate, 1942
- Salary then: 25 cents per hour
- That salary today: $21,100 per year
Bruce Nordstrom — of the retail giant name — got his first job with his family's company when he was just nine years old. During World War II, the now-billionaire worked at the stockroom of the retailer's shoe room for 25 cents an hour, which his father paid out of his own pocket. Nordstrom's career with the company skyrocketed and from 1963 to 2006, he helped the retailer grow from seven shoe stores in the Pacific Northwest to 156 stores in 27 states and a chain of European boutiques.
- Net worth: $5 billion
- First job: Magazine owner, 1966
- Salary then: N/A
Richard Branson isn't known for doing anything on a small scale, so it may not surprise you to learn his first job was publishing his own magazine. After dropping out of high school at 16 years old, he started a youth culture magazine called Student, which was for students and run by students.
The first edition sold $8,000 worth of advertising, which covered the first run of 50,000 copies. Branson actually started Virgin as a mail-order business to help fund his magazine efforts and it later evolved into record sales and eventually, a record label.
- Net worth: $72.8 billion
- First job: McDonald's fry cook, 1980s
- Salary then:$2.69 per hour
- That salary today: $8 per hour
Amazon founder Jeff Bezos has come a long way from his summer job flipping burgers at McDonald's. It was there he learned to get down to business and get his hands dirty — literally.
"My first week on the job, a 5-gallon, wall-mounted ketchup dispenser got stuck open in the kitchen and dumped a prodigious quantity of ketchup onto every hard-to-reach kitchen crevice," Bezos told author Cody Teets. "Since I was the new guy, they handed me the cleaning solution and said, 'Get going!'"
- Net worth: $75.6 billion
- First job: Newspaper deliverer, 1944
- Salary then:$175 per month
- That salary today: $2,433 per month
Buffett managed to squirrel away $2,000 by the time he was 15 and invested $1,200 of it in a 40-acre farm, where he had a profit-sharing deal with the farmer. Over his decades of investing, Buffett never lost touch with his roots — in 2012, he challenged Berkshire's annual meeting attendees to a newspaper toss contest.
- Net worth: $56 billion
- First job: Software engineer, 2006
- Salary then:$0 — Zuckerberg turned down a $1 million purchase offer from Microsoft and made the software open source.
Mark Zuckerberg was still in college when he founded Facebook, but he already had several other successes under his belt. In high school, Zuckerberg created music-recommendation software called Synapse, which was similar to Pandora.
In 2002, several software companies, including Microsoft and AOL, showed interest in purchasing Synapse and offered Zuckerberg a job, but he chose to enroll at Harvard University, instead — and the rest is history. Five years later Microsoft purchased a 1.6 percent share in Facebook for a cool $240 million.
- Net worth: $3.4 billion
- First job: Door-to-door sales, 1970
- Salary then: N/A
It might come as no surprise that Mark Cuban was an early entrepreneur. At 12 years old, this self-made billionaire went door-to-door selling boxes of garbage bags to pay for a pair of basketball shoes.
"Who's going to say no to a 12-year-old kid?" said Cuban. He credits this early lesson in hustling as the key to his success.
- Net worth: $13.9 billion
- First job: Software engineer, 1983
- Salary then: $500 selling price for computer game
- That salary today: $1,228
The Tesla founder has always been an avid fan of technology and space. When he was just 12 years old, Musk wrote code for his own space-themed video game called "Blastar," which he sold to PC and Office Technology magazine for $500. Recently, a software engineer from Google took the code and rebuilt the game to play on modern machines.
Like this story? Like CNBC Make It on Facebook