My laptop has 16GiB
My MacBook has 17,179,869,184 bytes of RAM, and not 16,000,000,000. Recall that 17,179,869,184 = 16GiB = 16 x 2^30, which is the correct measurement under IEC 60027-2. 16GB would be 16,000,000,000 = 16 x 10^9.
The differences between 1 KiB and 1 KB is not significant, but when you get up to the Gibibytes, the differences are indeed significant!
For more information, see https://physics.nist.gov/cuu/Units/binary.html