Originally Posted by

**chriscmartin** Not sure if i have posted this in the correct Forum so sorry if it is incorrect But i am desperate to get this answered.

I have an existing formula that i use in work to find out the OD of a coil from the weight, width and ID of the coil but i need to change it so i can find the weight from the ID, OD and width of the coil. The Formula i use is:

$\displaystyle OD=2000\left(\sqrt{\dfrac{1000W}{24.66c_w}}+\dfrac {ID}{2000} \cdot \dfrac{ID}{2000}\right)$

Please help its been driving me mad for the past 5 hours.