FitForce Planner is a tool designed for Marine Corps Force Fitness Instructors (FFIs) to support the creation of fitness training programs for groups of Marines. Programs can be composed of many days of workout sessions (or even many weeks or months), and they can be customized based on training experience according to three training levels: Beginner, Intermediate, or Advanced. The tool allows FFIs to schedule one main stressor per playcard (e.g., Agility & Threshold Training, Mobility/Recovery, Upper Body Strength) and, to facilitate periodization planning, FFIs can label two or more consecutive days with a specific phase (Endurance, Hypertrophy, Strength, Power, Deload). With FitForce Planner, FFIs can also create and manage groups and share workouts (or entire training programs) with others. FitForce Planner works best when opened in a browser on a personal computer (desktop or laptop). It was designed to function smoothly on Google Chrome (76+), Microsoft Edge (44+), and Mozilla Firefox (69+).