Critical Swim Speed Calculator
Calculate your swimming endurance threshold and optimize your training
Calculate Your CSS
Understanding Critical Swim Speed
What is Critical Swim Speed?
Critical Swim Speed (CSS) represents the theoretical swimming speed that can be maintained continuously without exhaustion. It's a crucial metric for endurance swimmers similar to lactate threshold in running.
Training Zones Based on CSS
Use your CSS pace to establish training intensities:
Zone 1: Recovery
CSS + 10-15s/100m
Zone 2: Aerobic
CSS + 5-10s/100m
Zone 3: CSS Pace
CSS ± 3s/100m
Zone 4: Threshold
CSS - 3-8s/100m
Zone 5: Sprint
CSS - 8+ s/100m