It's pertinent in terms of your relative income which is a statewide guideline formula. You can hire a lawyer or go to the courts self help website. Don't rely on non- lawyers for legal advice
Here is the calculator for California
You would put the disability in the disability section for income and not as wages/salary.
This answer is a general interpretation of the law and is not fact specific to your case. Likewise it does not create an attorney-client relationship. You should seek an attorney for a review of your specific facts and documents. My firm is All for the Family Legal Clinic, Inc. a nonprofit public benefit corporation that charges on a sliding scale based on income and family size. For a consultation contact us 510-999-7732 or at our website www.allforthefamilylegalclinic.org
While you can use the child support calculator provided in Ms. Ross' answer, I would highly recommend that you consult with an experienced California family law attorney to review the details of your case and help you formulate a legal strategy. I hope this helps and have a nice weekend.