I want to pay quarterly estimated tax for 2021. Calculate please

we can't. we have no access to your return.  type estimated in the search box. then use the jump to link to get to the estimated tax options worksheet.

or so a quick self-done calculation

if 1040 line 11 is $150K or more compute 110% of 1040 line 24 otherwise use 100%

form this subtract your estimated federal withholding for 2021

this result is the amount required to be paid on estimate for all of 2021

divide by 4

this is the amount to be paid on each of the following dates  4/15/2021 - late

6/15/2021, 9/15/2021 and 1/18/2022

In addition to Mike 9241's post above, please see the following link for additional guidance to help you prepare your estimated tax payment vouchers.

How to make estimated tax payments

How to calculate your estimated tax payments