How much this 1099-B affects your return (and refund) depends on how much taxable income it reported and what type of gain you had (long-term or short term). The tax rate applied to the gain depends on your personal marginal tax rate.
Gain is easy to calculate - Gross Proceeds (Box 1d) minus Cost or Other Basis (1e. The higher the gain, the more tax you owe and the lower your refund will be.
Type of gain is also easy - if you held the security for 1 year or more, it is long-term-gain; less than 1 year is short-term gain. You may already see this information in Box 2. Otherwise, TurboTax will calculate it from the information in Box 1b (Date acquired) and Box 1c (Date sold or disposed). Long-term gains are taxed at a lower rate than short-term gains.
