hashpower – Hash rate: algebraic equation

I recently made a publication in the stack, Calculate the hash rate in IOS, with the hope of deciphering how the hash rate is calculated when performing a comparative performance evaluation. The reason I wanted to do this is to compare with the results presented in Is it possible to mine cryptocurrencies with an iPhone? After days of searching the Internet, I came to the conclusion that calculating the hash rate is not as simple as it seems.

My thoughts

I had the impression, especially after reading How can I calculate the amount of hashes I generate per second?, Explaining the hash rate or the hash power in cryptocurrencies and how the hash rate of the mining hardware is calculated, that the calculation of the hash rate is done as follows:

Have collection of x number of messages (M) 80 bytes in size
Go through the records and calculate the sha256 (sha256 (M))
Divide the number of hashes calculated against elapsed time
# the result is the hash rate (in seconds, since the elapsed time is in s)

After doing so, I see results of up to 24,000 hashes per second, or 24KH / s. Obviously, this is alarming, since the reference article I'm trying to compare has these results:

The iPhone 6 has 25/30 Hash Rate (H / s)

The iPhone 8 55 H / s.

The iPhone X (iPhone 10) 65 hashes per second.

Later, I continued my search, and I stumbled upon this Stack publication, how to calculate the hash rate of your platform, and the accepted response mentions that the hash rate is something that is defined empirically. While I do not doubt the author, now I find it difficult to determine what the hash rate really is. (Does the "nonce" have any impact on the calculation of the hash rate? That is, is the standard hash rate determined when calculating the number of times my machine can guarantee that the hash result begins with 3 (or 5, or 7) zeros to the left in 1 second?)

TL; DR

I want to calculate a hash rate for my IOS device. What algorithm and algebraic expression should I use to calculate the hash rate, in order to compare my results with other devices, such as laptops and graphics cards?