Question: how to calculate a percentage spread?
Answer: To calculate the bid-ask spread percentage, simply take the bid-ask spread and divide it by the sale price. For instance, a $100 stock with a spread of a penny will have a spread percentage of $0.01 / $100 = 0.01%, while a $10 stock with a spread of a dime will have a spread percentage of $0.10 / $10 = 1%.