Correct Usage of the wireless calculator

RouterOS Wireless Networking
1

So I am a noob 8<) and was trying to use the wireless calculator found here: https://www.mikrotik.com/test_link.php

So I was comparing the SXT5 vs the SXT2 and running different numbers…

On the SXT5 at MCS0; 30dBm / -93dBm
On the SXT5 at MCS7: 26dBm / -71dBm

I then enter 16 db for the antenna.

0 for cable (since I am doing POE to unit)

With those to sets of numbers, I get 33 Miles at MCS0, but under 2 miles for MCS7. Is that correct, or I am missing something somewhere?

I looked up the definitions of MCSO and see that it is roughly 10X the data from 0 to 7, so I expected it to be lower, but I was surprised it was that much shorter distance.

With the Sextant, TX/RX at MCS7: 24dBm / -78dBm & 18 db antenna, I am getting over 4 miles.

Just want to make sure I am calculating this correctly when choosing an antenna.

Thanks!

2

MCS0 is low speed (about 6/12/24 Mbit/s), low signal/noise requirement, so it work on longer distance;
MCS7 is high speed (about 75/150/300 Mbit/s), so it work on shorter distance