I have a 1099-B for company RSU's. The cost basis section is blank so I'm trying to determine it, however the sale was done in DKK. How do I enter/calculate?

To calculate and enter the cost basis for your RSUs (Restricted Stock Units),  here is a guide you may use.

1. Determine the Fair Market Value (FMV) on Vesting Date. The cost basis for RSUs is typically the FMV of the shares on the day they vested. This value is often included in your income on your W-2 form. If it's not explicitly listed, you can check your payslips or other records from the vesting date.
2. Convert the FMV from DKK to USD: Since the sale was in Danish Kroner (DKK), you'll need to convert the FMV to USD using the exchange rate on the vesting date. For example, if 1 DKK equals 0.15 USD, multiply the FMV in DKK by 0.15 to get the USD equivalent. 

Presently, the exchange rate is 1 DKK=.15 USD.  It may have been different on your vesting date so you may need to check historical prices.  This is a good website to research this.