I had a large one time long term capital gain in first quarter of 2017. Do I pay 1/4 of tax due for the first estimated payment or does it need to be more?

[ChrisV]

You will technically need to pay more in estimated taxes in the first quarter as the IRS calculates estimated taxes due on a quarterly basis. This IRS publication goes into all the details, but the worksheet 2-14 (roughly half way down) shows an example of how you would want to calculate the estimated tax by quarter.

It is ok for your first quarters estimated taxes to be larger than future quarters payments, and this will prevent you from being penalized by the IRS for late tax payments (which will be charged interest and penalties by the IRS). 

https://www.irs.gov/publications/p505/ch02.html#en_US_2017_publink1000194657