Commission Calculation using Sumifs

Need help calculating commissions. I'm thinking I can use the SUMIFS function. For example, there is a commission range of $$0-$200,000 is 35%; $201,000-$300,000 is 40%; $300,001-$400,000 is 45% and so on. I need to be able to calculate when the % changes as the gross profit is earned. I've attached my spreadsheet to assist.

Thanks!