# McDonald’s Math

If I told you x+y = 5 and x+2y = 7, you would be able to determine that x=3 and y=2. Basically, we had an x and y, and when we added another y, it went up by 2. So y must equal 2. This is algebra. So let’s apply this to McDonald’s.

Sausage Biscuit – \$1. This is a sausage patty and a biscuit. Nothing else.
Sausage Biscuit with Egg – \$3.09. This is the same above, but with an egg on it. In this case, we’re paying \$2.09 for the egg.

Sausage McMuffin – \$1. This is a sausage patty, slice of cheese, and an English muffin.
Sausage McMuffin with Egg – Same as above, but with an egg on it. \$3.09. Again, it’s \$2.09 for the egg.

Now, if we look at the breakfast combo, which is adding a hashbrown (\$1 on the Dollar Menu) and a coffee (\$1 also on the dollar menu). So separately, it’d be an addition \$2. So what does it take to turn a breakfast sandwich into a combo? Anywhere from \$1.45 (Steak, Egg, & Cheese Bagel) to \$1.90 (most meals). The bagel sandwiches on their own are over \$4, so maybe that’s how they can offer a “better” discount for the meal. But for the other ones? You’re usually saving \$.10 for the breakfast combo. And I don’t like coffee, so I usually have to substitute it for something else.

Now onto lunch and dinner.

The McDouble – \$1. This is a bun, two hamburger patties, a slice of cheese, and ketchup, mustard, onions, and pickles.
The Double Cheeseburger – \$1.49. Same as above, but with 2 slices of cheese instead of 1. So…..\$.49 for a second slice of cheese.
Hamburger – \$.89
Cheeseburger – \$.99. So the first slice of cheese is \$.10.
McDouble – \$1. Basically a cheeseburger with another patty. So the second slice of cheese will cost \$.49, but the second patty of meat is a penny.

So for lunch, when you make it a combo, you add a medium fry (normally \$1.69) and a medium drink (\$1.49). So separately making something a combo would cost an additional \$3.18. So what are you actually saving? Well, it depends on which sandwich you’re making a combo. For the most expensive sandwiches, a combo costs \$2 more. For the Double Cheeseburger, making it a combo costs an additional \$2.90. A savings of \$.38!

A Double Cheeseburger Combo (which is a Double Cheeseburger, medium fry, and medium drink) – \$4.39.
A McDouble, Medium Fry, and Medium Drink – \$4.18. Saving \$.21 by not getting a combo and forgoing a single slice of cheese.

Now let’s talk about drinks. Going from a medium to a small (which is on the dollar menu) will save you \$.49. If you’re in the restaurant and you can get free refills without the hassle of going to the counter, it might be worth it. But if you’re eating at home and skip the drinks altogether? Well, you probably wouldn’t skip them altogether, but drink something from home. Let’s look at milk. At McDonald’s, the milk is \$.89 for 8 fl oz. You can get a gallon of milk for \$3.00 in some places. So how does this translate? Well, here’s some screenshots from “Simple Pricebook“. (Shameless plug: I wrote Simple Pricebook.  It’s available on Android devices here and iOS devices here for just \$.99)

So what does this tell us?  The top is the price of milk at McDonald’s.  If we bought the same quantity of milk (8 fl oz) at the Aldi rate, it’d be like paying \$.18.  So we’re saving \$.71.  Of course, we’re actually buying a gallon.  Now if we reverse that logic:

Buying a gallon of milk at McDonald’s would cost \$14.23!  No one would pay \$14 for a gallon of milk! So why would you?

The thing I don’t get about the pricing scheme is that it makes us actually spend less at McDonald’s.  For breakfast, we all just order off the dollar menu (sandwich and hashbrowns) and spend \$8.  If we all ordered sandwiches with egg and hashbrowns, we’d be spending \$16.  Over \$20 if they were combos.  Run the cost of soda, orange juice, or whatever you want with Simple Pricebook and see what results you get.

Yes, making food at home will always be cheaper. And sometimes if you’re busy, tired, or for some other reason, you don’t want to cook.  But if pouring my own glass of milk will save me \$5 for the meal, I’m going to do it.