You only owe the self employment tax on the Net Profit on Schedule C. Do you have expenses you can write off on Schedule C? And if you already paid the max Social Security tax on the W2 wages you only owe the 2.9% for Medicare. The max wages for 2025 is 176,100.
One thing you can do is change your W2 withholding to take out more to cover the SE tax for 2025. Here are the blank Estimates and instructions (the actual 1040ES forms are at the very bottom so scroll way down)
http://www.irs.gov/pub/irs-pdf/f1040es.pdf
Or you can pay directly on the IRS website https://www.irs.gov/payments
Be sure to pick the right kind of payment and year.....2025 Estimate
Here is some IRS reading material……
IRS information on Self Employment
http://www.irs.gov/Businesses/Small-Businesses-&-Self-Employed/Self-Employed-Individuals-Tax-Center
Pulication 334, Tax Guide for Small Business
http://www.irs.gov/pub/irs-pdf/p334.pdf
