There are too many variables for anyone to know that in a user community forum.
You can try TurboTax free and quick estimator tool called TaxCaster.
https://turbotax.intuit.com/tax-tools/calculators/taxcaster/
You appear to be using Live Self-Employed, which is the most expensive of the Online TurboTax products. That Live feature allows for on-demand help from a CPA/EA tax expert during return preparation and a review of your return prior to filing. The fee is $200 for a Federal return and $55 for a state return. And if you choose to pay the fees out of the Federal refund, there is an additional $40 service fee ($45 for California filers.)
Is Live Self-Employed the product you wanted? If not, that Live component can be removed, if you want regular Self-Employed Edition ($120 for Federal and $50 for state).
FAQ: What is TurboTax Live?
https://ttlc.intuit.com/community/choosing-a-product/help/what-is-turbotax-live/01/27191
FAQ: How do I remove Live?
https://ttlc.intuit.com/community/downgrading/help/how-do-i-remove-turbotax-live/01/27312
For the most simple case: $42,000 income minus $12,200 standard deduction = $29,800 taxable income. The tax on that, from the tax table is $3385. If your federal withholding is more than that; the difference will be your refund.
But for most people, There are too many variables for the simple answer; such as the type of income, your dependents, filing status, credits, withholding etc..