Dilutions are really simple if you keep track of what’s coming in and what’s coming out. Our dilutions calculator makes it even easier with just three numbers to enter and the result immediately being displayed. The formula behind it is Concentration 1 x Volume 1 = Concentration 2 x Volume 2. You have to choose the right units for it to work so make sure you use the dropdown boxes next to the fields. The missing number (the one you haven’t entered) will apear at the bottom, in the units specified in its dropdown box. Find it useful? Missing a calculator? Why not leave a comment below and help thousands of other readers with your question?
Maria Fuentes, PhD
I did my PhD in the Department of Chemical Engineering at Imperial College London. My research focused on mathematical modeling of the cell cycle in leukemia and involved experiments with cell lines. During that time, I had to count cells with a hemocytometer so often to track growth that I got tired and decided to build an app, HemocyTap, and share my knowledge on the topic here to help as many people as possible.
Hi there.
I’m having a few problems with the dilution calculations. Below are a few questions I am struggling with:
You are attempting to measure the T. pyriformis IGC50 of a new drug candidate as part of an ecotoxicity and environmental impact study. You are required to prepare solutions of the new drug candidate as part of the study.
a) Show calculations for the preparation of a 100 mg/L stock solution of the test substance in a 250 mL volumetric flask.
b) 5 mL of the stock solution was diluted to 50 mL in a volumetric flask. What is the dilution factor?
c) If you are required to prepare a 1 in 5 dilution of the solution in Q7 b) in a 25 mL volumetric flask:
i. How much of the solution in Q7 b) do you need to perform this dilution?
ii. What is the concentration of this diluted solution in mg/L?
Hope to hear from you soon
What part are you struggling with?
Wow! That was easy! I was shocked! Ive had some math. I have forgotten how to do so much. Thank you!
Wow, THANK you so much. I’m a 1st-year undergrad in Biomed and I felt silly that I really didn’t know how to do this. made it so simple and will be using a lot more in the future. thank you so much 😀
No problem Laura, happy to help!!