what is the dry measuring cup equivalent of 3 oz of flour?

Hi roberta18,

Using the Good Cooking's Cooking Measure Converter, 3 ounces = 0.375
cups(which is a little over 1/3 cup).

http://www.goodcooking.com/conversions/liq_dry.htm

I hope this helps.

Best regards,
Rainbow

rainbow's answer is for fluid ounces

If you are talking about weight:

the correct technique of measuring flour consists of 3 steps:
(1) Sift the flour
(2) Fill the measuring cup to heaping full
(3) Level cup with a straight-edged spatula

When flour is measured by this method which eliminates packing of the
flour as much as possible, one cup should weigh about 4 ounces or 112
grams.