Calculate interest on your legal claim with our free calculator. Add pre-judgment and post-judgment interest to maximize your recovery. Interest rates vary by state and claim type. Our calculator includes: statutory interest rates for all 50 states, pre-judgment interest from the date of breach, post-judgment interest from the date of judgment, and compound interest where applicable. Many people forget to add interest to their claims, leaving money on the table. Interest can significantly increase your recovery, especially for older debts. PettyLawsuit helps you calculate and claim all interest you're entitled to. Our demand letters include interest calculations and cite applicable state interest laws. When filing in court, we ensure your claim documents accurately reflect interest owed. Get started today with a demand letter for $29 and maximize your recovery.