This calculator shows the implied discount investors are attaching to CBS because of the voting shares, mostly held by Sumner Redstone.

The main inputs are the class A and B share prices, the P:E ratio that would apply if there were a single class of shares, and the premium at which the company might buy out A shares.

The calculator works out a theoretical single share class market cap for CBS, the prevailing discount to that valuation, and the remaining uplift for B shareholders if A shares were bought out.

You can change any of the numbers in blue to reflect your assumptions.

For more interactive calculators and agenda-setting comment visit: BREAKING VIEWS