Read and follow what is reported in which box(es) with which code(s). You might have Tips reported to the employer, or tips allocated to the employee. Are you trying to further split it or deduct it somehow?

Such as:

"Allocated tips are tips your employer assigned to you in addition to the tips you reported to your employer for the year. If your employer allocated tips to you, that amount will appear in Box 8 of your W-2. No income, social security, or Medicare taxes are withheld on allocated tips. These taxes must be figured on Form 4137 using the amount from Box 8"

"If your employer did not collect all social security and Medicare taxes you owe on tips, the amount may be shown in Box 12 of your W-2"

And: https://www.irs.gov/taxtopics/tc761