Cars & Other Vehicles Drop per second to milliliters is the conversion rate. The Drop is equal to 0.05 mL.If you divide the gtt value by 20, you can convert it to mL. Related Posts:How do I find out my GTT number?How many bottles of water in a gallon?How long does it take to convert MP4 to AVI?How many cups of tea are in a cup? - Answers.