Contributing $3,500 per year to a Roth IRA throughout your 40s, assuming a 10% annual return, will result in accumulating $378,000 by age 65.
"if you only contribute half of the annual limit which is $3,500 per year in your 40s and you assume a 10% annual return you would still accumulate $378,000 by the time you're at the age of 65"