17,000 McDonald's Straws to Fill a Bathtub

Here's a math problem you never asked for but absolutely need: how many times would you have to fill a McDonald's straw to equal a bathtub's worth of water? The answer is roughly 17,000 times.

That's not a typo. Seventeen thousand trips from straw to tub, assuming you're working with a 34-gallon bathtub and haven't lost your mind somewhere around straw number 8,000.

The Straw That Broke the Calculator

McDonald's straws aren't your average fast-food accessories. They're actually slightly wider than standard straws—about 0.02 inches larger in diameter. This wasn't an accident. McDonald's and Coca-Cola conducted consumer research to determine the optimal straw width, finding that a wider opening lets more liquid flow through with each sip.

The result? A straw that holds approximately 7.5 milliliters of liquid—or just over one-and-a-half teaspoons. That extra width makes a huge difference when you're trying to drink a thick milkshake, and apparently, when you're calculating bizarre bathtub statistics.

Breaking Down the Numbers

Let's do the math:

• A 34-gallon bathtub holds about 128,700 milliliters of water
• Each McDonald's straw holds approximately 7.5 milliliters
• 128,700 ÷ 7.5 = 17,160 strawfuls

If you somehow committed to this task, filling and emptying a straw once every three seconds without breaks, you'd be at it for about 14 hours straight. Your bath would be cold. Your dedication would be legendary.

Why Bathtubs Vary So Much

A 34-gallon tub sits on the smaller end of the bathtub spectrum. Standard bathtubs typically range from 40 to 60 gallons, with larger soaking tubs holding 80 gallons or more. Luxury two-person tubs can exceed 100 gallons.

Using a bigger bathtub would obviously require more strawfuls. A 50-gallon tub? That's about 25,000 straws. A 100-gallon jacuzzi-style tub? You're looking at 50,000 strawfuls—at which point you should probably just use the faucet.

The Science of Sipping

There's actually fascinating physics behind why McDonald's chose their specific straw dimensions. The diameter directly affects how much force you need to draw liquid through. Too narrow, and thick shakes become a workout. Too wide, and drinks disappear before you've left the drive-through.

According to Dr. Talia Lerner, a neuroscience professor at Northwestern University, that wider diameter "allows more liquid volume through, meaning you would consume more sugar water faster." It's engineering optimized for maximum beverage enjoyment—and apparently, for confusing bathtub math.

So the next time you're sipping a McFlurry, consider this: you'd need to refill that straw seventeen thousand times before you'd have enough liquid for a modest soak. Sometimes the most useless facts are the most satisfying.