[Request] How accurate is this?(i.redd.it)

Despite other comments having correct formulas, their way of approaching this calculation is off. They assume all the meows would be concentrated into a singular point, which although makes for a fun thought experiment, is physically impossible.

Instead, we need to create a sphere-shaped wall of cats facing inwards to a centralized point and find out how loud the combined force of all the meows would be at the center point inside of that sphere.

This will not take acoustic reflections into account as cats are extremely fluffy and do not function very well as sound transducers.

Due to the loose definition of the word "cat" which can often include animals like bobcats, cheetahs, or tigers, we'll be restricting ourselves to house pets only, which would put our number of cats at around 373 million according to Statista.com. We'll use this as our figure.

Thanks to extremely informative videos such as this one, we know that what we can only assume to be an average-sized cat can fit through an 11cm circular hole, though for easier calculations we'll translate that into a hexagonal shape measuring 11cm across the narrowest point. This will be the base estimate of how much space each cat would need in our hypothetical wall sphere of meows.

(Side note: although the inclusion of kittens would likely decrease our estimated hole size, kittens are often significantly more quiet than their full-grown and we can only assume a cat sized tube filled with kittens would produce the same decibel levels as a singular fully grown cat)

Thanks to this handy website, we now know that each cat would take up an average of 104.79cm², we'll round this down to 100cm² (0.01m²) as the air escaping the lungs of the cats during their screaming process would naturally make them thinner.

From here, we simply multiply the area of each cat by the number of cats to find the total area of our noise sphere.

0.01m² per cat × 373,000,000 cats = 3,730,000m² of cats

Another handy website let's us know that our cat sphere with a surface area of 3,730,000m² would have an internal radius of 544.815537m, which we will round up to 550m, just above half a kilometer or 1/3rd of a mile.

At this range, a single cat meow of 75db/1m would be 20.2db, but multiplying this number with the 373 MILLION cats where every doubling equals 3db worth of volume gain, you end up with the massive, thundering roar of...

...105.9db

Huh.

All things considered, that's not all that loud. A larger Bluetooth speaker or a portable PA system such as the Bose S1 Pro would rival that number at an average listening position of 10 to 15 feet. The best comparison i could in regards to both loudness and frequency range would be a distorted guitar played through a small-ish amplifier, like a Fender Princeton with the volume at around 6 or 7.

Although this answer of the raw volume level is somewhat disappointing, there's still a way to make things fun again.

If we were to stretch our cat sphere out to a roughly 1km times 2km straight wall, we could instead calculate how far these cats could be heard from, which in our case would be just about THIRTY THOUSAND METERS, or 18.6 miles.

This means that if our wall of every pet cat currently alive all meowing at once was placed in Calais, France, you'd be able to hear them from Dover, England as if there was a cat standing right in front of you.

You'd also be able to hear faint traces of meowing all the way from Norway, like the hum of a refrigerator.

In Canada, the sound would still be detectable, like a soft whisper.

If placed strategically, our single 2km wide cat wall would be heard from approximately half the global population at once. Now that's impressive.