Contracts

• Options are traded in contracts, not as individual derivative units.  Each contract represents a certain number units of the underlying asset.  This number is different for different types of asset worldwide.
• Therefore, when you see a US equity call option premium of say, 1.45, you will have to pay $1.45 * 100 for just 1 contract.  1 contract is the minimum amount you can trade and for US Equity options 1 contract represents 100 individual shares.

The following table outlines the amount of underlying securities that represent 1 contract for a few different markets where options are traded on an exchange:

Therefore, when you trade a covered call you are only "covered" if you are trading the same number of units on each leg of the trade.

For Example:

If you are wanting to sell 3 contracts of SLB 80.00 strike calls at 3.50, you will receive a premium (before commissions) of $1,050.  But you will need to buy 300 SLB shares in order to be "covered".  This will be at a cost of 300 * the SLB share price.