Trumpu2019s tax proposal calls for a top self employed tax rate of 25% and a top corporate rate of 15%. Assuming tax brackets stay about the same you would be in the top brackets, so $500K of net profit in a single owner or multi owner LLC taxed as a partnership or sole proprietorship total tax is $125,000 compared to approximately $233,000 under the current tax plan.If the LLC is taxed as a C Corp, then total tax would be $75,000 vs $170,000 under the current plan. That is without regard to any compensation that is paid to the owner(s).UPDATE: This questions is getting a lot of views here in Dec 2023 and I feel compelled to note that the answer was written on Nov 9, 2023 well before the final tax reform bill was passed. What was proposed is not what was passed, but the self employed and corporate effective tax rates did drop, just not as drastically as originally proposed.