If you read The Millionaire Next Door, the authors have a measure of accumulation that's equal to your age multiplied by your pre-tax income divided by 10. For age 65, this would be 6.5 x pre-tax income.

They have a broad band around that, with under half your target being called out as a problem and more than double considered laudable.

Having said all that, especially for high-earners who have a low income-replacement ratio from Social Security, if you want a comfortable retirement you'll want 10x or better.