PacerX: Race Predictor

How fast could you race today?
PacerX turns the runs already in Apple Health into personalized 5K, 10K, half marathon, and marathon predictions—then shows you the training evidence behind every estimate.
Built for runners who want more than a workout list or a one-result pace calculator, PacerX looks across your recent training, best efforts, trends, pace, heart rate, effort, weather, elevation, and consistency to help you understand where your fitness is heading.
SMARTER RACE PREDICTIONS
See realistic estimates for 5K, 10K, Half Marathon, and Marathon based on your recent training. Open any prediction to understand the runs and signals that influenced it.
PREDICTION HISTORY
Track how your projected race fitness changes over time. See when your training is moving the needle—and when your estimates are holding steady.
DEEP ANALYSIS
On supported devices, Deep Analysis uses Apple Intelligence to give you a deeper explanation of what your recent training says about race readiness. PacerX uses on-device processing where appropriate and can use Apple Private Cloud Compute for supported Deep Analysis requests.
COMPARE YOUR RUNS
Open any run and compare it with a relevant past workout—or choose one yourself. Review pace and heart-rate charts, side-by-side metrics, and context such as route, distance, effort, weather, and elevation.
FIND YOUR BEST RUNS
Discover validated personal bests and standout efforts across your running history, including 1K, mile, 5K, 10K, half marathon, marathon, longest run, most climbing, most consistent splits, and more.
SEE THE FULL PICTURE
Review weekly mileage, monthly and yearly trends, pace, heart rate, cadence, elevation, perceived effort, shoes, running surface, weather, and other context from your training history.
PRIVATE BY DESIGN
PacerX reads your running data from Apple Health. No account is required, there are no ads, and your running history isn't used to build advertising profiles. Optional Deep Analysis may securely process derived training insights using Apple Private Cloud Compute, where request data is not stored.
PacerX doesn't replace your coach or training plan. It gives you a clearer picture of what your training says—so your next conversation, workout, or race decision starts with better context.
Understand your training. See what you're ready for. Keep moving forward.