CGT on Gifted Shares

I was gifted shares a number of years ago. I'm now about to sell them. To calculate if a gain has been made do I calculate the difference between price at time of obtaining the shares and the selling price. Or as they didn't cost me anything is the whole value realised when sold the gain I should use for the CGT calculation? thanks

Hi Jimmo,
A price would have been given at the time of transfer.
If gifted from someone other than your spouse/civil partner, it will be the value at date of transfer.
If from your spouse/civil partner it is what they originally paid.
Thank you.