Back in 2013 and based on 2012 prices, it was determined that the average Big Mac would jump $1.28 if the minimum wage increased from $7.25 to $15. This was based on the average price of a Bic Mac at $4.20. Mathematically, this means a 30.4% increase in price. It also means a roughly 4% increase for every dollar of minimum wage increase, and this is before any other inflationary costs for food, utilities, etc. are factored in.
Of course,nobody just buys a Big Mac. They usually buy a "Meal" which includes the burger, fries, and Coke. Today, with a $9 minimum wage in California, the average "Meal" costs $7.67. Now, if I'm a single guy and the minimum wage is now $15 or around $31,000 a year, my after tax income will be about $12/hour. Total taxes being roughly 20%. With the increase to $15, that once $7.67 "Meal" should be about 24% higher; assuming an increase of $6 from the current $9. Thus, to treat myself and a friend, it will now cost $20.73; assuming a 9% sales tax in Los Angeles.
Therefore, I would have to work almost 2 hours in order to pay for this simple date. It's no wonder their losing business. No one can afford to eat there anymore. Especially millennials with their incomes around $37,600. A $15 minimum wage just may be the death knell for McDonald's and the rest of the fast food industry. A primary source of minimum wage jobs in this country.
Los Angeles is the largest city in America with a $15 minimum wage: http://money.cnn.com/2015/06/14/news/economy/los-angeles-minimum-wage-15-garcetti/
McDonald's Hourly Wages By Job Type: http://www.glassdoor.com/Hourly-Pay/McDonald-s-Hourly-Pay-E432.htm
Taxes on a Worker Making $30,000 in California: http://www.taxformcalculator.com/tax/30000.html
2012 Big Mac Price: http://big-mac-index.findthedata.com/
McDonald's Fast Food Prices: http://www.fastfoodmenuprices.com/mcdonalds-prices/
Average millennial income: https://www.google.com/search?q=average+millenial+income&ie=utf-8&oe=utf-8