I think AnnetteB6 is confused about the types of employment that you have. It appears that you have income from self employment and also income from another employer (in which, I assume, you do not have a controlling interest).
Any retirement contributions made on your behalf at your W-2 employer have no bearing on the amount that you are eligible to contribute to a SEP-IRA from your self-employment income. Your maximum SEP contribution for 2019 from self-employment income is 20% of net earnings, or $56,000, whichever is less. Net earnings is net profit minus the deductible portion of self-employment taxes.
To calculate your maximum SEP IRA contribution allowed for a Schedule C business, multiply your net Schedule C income by 92.35%. Then multiply that result by 20% if your plan contribution rate is 25%.
If your plan contribution rate is something other than 25%, you will need to use the table in IRS Publication 560, page 23 to determine the percentage to use to calculate your maximum contribution (IRS Publication 560).
IRS Publication 560 also provides a worksheet that can be used to calculate your deduction.
Your SEP IRA contribution has no relation to your W-2 income. It is only based on your Schedule C net income.
The maximum allowed for 2019 is $56,000.
[edited 3/24/2020 | 9:16 am PST]
I think AnnetteB6 is confused about the types of employment that you have. It appears that you have income from self employment and also income from another employer (in which, I assume, you do not have a controlling interest).
Any retirement contributions made on your behalf at your W-2 employer have no bearing on the amount that you are eligible to contribute to a SEP-IRA from your self-employment income. Your maximum SEP contribution for 2019 from self-employment income is 20% of net earnings, or $56,000, whichever is less. Net earnings is net profit minus the deductible portion of self-employment taxes.