I think you need to do some extensive reading about birth control pills. It's not quite as simple as you seem to think (based on the absolute lack of specificacy in the question).
I looked up a few and they contained no straight "estrogen" but rather estradiol which is the primary estrogen of importance (there are other estrogens) during a womans fertile years. You also need to take into account progesterone.
The number you were really after is 20 to 50 micrograms; 30-35 is considered mid range, 20 low and 50 high.
Search for questions
Still looking for answers? Try searching for what you seek or ask your own question.
Updated 15 Dec 2014 • 1 answer
Updated 24 Dec 2014 • 2 answers
Updated 9 Feb 2016 • 1 answer
Updated 5 Aug 2016 • 1 answer
Updated 4 Mar 2019 • 1 answer