Swim Pace Calculator

Personalized Training

The Swim Speed and CSS Calculator gives you swim training zones that match your current swimming abilities. This means your training sessions will be more focused and effective, leading to better results whether you're in the pool or swimming in open water.

Track Your Progress

Your Critical Swim Speed (CSS) is a reliable way to track your swim fitness over time. By checking your CSS regularly, you can see how much you’re improving and adjust your training to keep getting better.

Plan Your Race Strategy

Knowing your CSS helps you plan how fast you should swim during a race. With this information, you can avoid starting too fast and burning out, ensuring you perform your best throughout the entire race.

Set Goals and Stay Motivated

Having clear goals based on your CSS can be very motivating. When you know what you’re aiming for, it’s easier to stay focused and work toward better race times.

Once you know your CSS, you can set up different training zones:

• Zone 1 (Easy): Recovery and basic endurance training. CSS + 20-30%.
• Zone 2 (Steady): Aerobic endurance training. CSS + 15-20%.
• Zone 3 (Moderately Hard): Training at your lactate threshold. CSS + 10-15%.
• Zone 4 (Hard): VO2 max training. CSS + 5-10%.
• Zone 5 (Very Hard): Speed training. CSS to CSS + 5%.

These zones help you focus on different aspects of your swimming fitness, making sure you’re working on all the necessary skills.

The CSS calculator is based on solid science from exercise physiology and endurance training. Critical Swim Speed is closely related to the anaerobic threshold, a key factor in endurance sports like swimming. This concept is well-supported by scientific studies and is widely used by coaches.

For more on how CSS is used in training, you can check out Swim Smooth's guide on Critical Swim Speed or explore Jack Daniels' insights on training thresholds, which can also apply to swimming.