How many option contracts can I afford to buy based on my account's buying power?

How this is calculated

• Cost per contract equals the premium per share multiplied by 100 shares, the standard equity option contract size.
• Maximum contracts equals your buying power divided by the cost per contract, rounded down to a whole contract.
• This tool assumes you are buying, going long, calls or puts, where the full premium is paid up front, the standard requirement at most retail brokers.
• It uses the ask price you enter. Your actual fill can differ because of the bid-ask spread. See the Slippage Cost Calculator to estimate that separately.
• This does not calculate margin requirements for selling, or writing, uncovered options, which are set by your broker and are typically more complex than a simple debit calculation.
• Buying the maximum number of contracts your account can technically afford is rarely a responsible position size on its own. Check this number against your normal risk-per-trade rule before deciding how many to actually buy.