The N.Y. Times reports that about 95.0% of all votes have been counted, with Harris at 71.7M and Trump at about 75M:
These 95.0% amount to 148.8M, so that means there are about 7.8M uncounted (that’s 148.8M / 0.95 * 0.05), for a total number of about 156.6M. (All numbers are approximations.)
Most of those not yet counted votes are in California (4.2M there, since 25% of the votes there remain uncounted); quite a few are from Oregon, Washington, Arizona, Utah, and Colorado. These on balance tilt Democrat; so far California and Washington have split roughly 60-40 Democrat, though the other states are closer to 50-50 (and Utah has been splitting 60-40 Republican). This suggests that the 7.8M will split roughly 4.3M Harris to 3.3M Trump or thereabouts. Put together that means a likely final total of roughly 76M Harris and 78.3M Trump or so, give or take a few hundred thousand. (Maybe 2.3M or a bit more will go to third-party candidates.)
Again, when thinking about the 2020-to-2024 vote gulf, it’s important to compare the 2020 final results with projected 2024 final results (or just wait until the 2024 final results are in), rather than 2020 final results with early 2024 results.