Cycling Race Pace Calculator
BetaUpload your GPX course file and get detailed race pace projections based on your FTP, weight, and weather conditions. Our free calculator uses physics-based modeling to estimate your finishing time, considering elevation profiles, wind direction, and aerodynamic factors.
Beta Feature
This tool is in beta. Results are estimates based on physics modeling. Actual race times may vary due to factors like fatigue, drafting, and road conditions.
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GPX files only (max 10MB)
Pacing Strategy
How the Physics Model Works
Our cycling race pace calculator uses a comprehensive physics-based model to predict your finishing time. Unlike simple pace calculators, we account for the real-world forces that affect your speed on every segment of the course.
Power Balance Equation
At every point on the course, we calculate the balance between your power output and the resistive forces: aerodynamic drag, rolling resistance, and gravity on climbs/descents.
Numerical Integration
We integrate segment-by-segment along your route, calculating speed changes based on gradient, wind conditions, and your power output to build an accurate time prediction.
Air Density Modeling
Elevation affects air density, which impacts aerodynamic drag. Our model accounts for altitude changes along your course for more accurate predictions.
Pacing Strategy
The calculator applies intelligent pacing based on terrain - pushing harder on climbs where aerodynamic losses are lower, and optimizing power on flat sections.
GPX Upload Requirements
For the most accurate race time predictions, your GPX file should meet these requirements:
- Elevation data: GPX files with barometric or corrected elevation provide better accuracy than GPS-only elevation.
- File size: Maximum 10MB. Larger files may need to be simplified first.
- Track points: Routes with at least 100 track points provide smoother analysis.
- Sources: Export GPX from Strava, Garmin Connect, Komoot, RideWithGPS, or any cycling computer.
How FTP, CdA, Weight and Wind Influence Your Predicted Time
Understanding how each parameter affects your race time helps you input accurate values and interpret results:
FTP (Functional Threshold Power)
Your FTP determines the sustainable power you can hold for the race. Higher FTP = faster times. A 10W increase in FTP can save 2-5 minutes on a 40km time trial depending on the course profile. FTP matters more on flat courses where aerodynamic drag dominates.
CdA (Coefficient of Drag × Frontal Area)
CdA measures your aerodynamic efficiency. Typical values range from 0.20-0.25 m² for time trial positions to 0.30-0.40 m² for road positions. Reducing CdA by 0.01 m² can save 30-60 seconds per hour at race pace. CdA matters most at higher speeds on flat terrain.
Total Weight (Rider + Bike)
Weight primarily affects climbing performance. Each kg saved can mean 1-2 seconds per km on steep climbs. On flat courses, weight has minimal impact. For hilly courses like Alpe d'Huez, weight is the dominant factor in determining your finishing time.
Wind Speed and Direction
Wind can dramatically affect race times. A 15 km/h headwind can add 5-10 minutes to a 40km time trial. Our calculator accounts for how the wind angle changes as you follow the course, giving you a realistic estimate of wind impact rather than a simple headwind/tailwind calculation.
Why Use This Instead of Best Bike Split?
Best Bike Split is a great tool, but our free cycling race pace calculator offers key advantages for most cyclists:
100% Free
No subscription, no hidden costs. Use it as often as you need.
No Account Required
Start calculating immediately. No signup, no email required.
Fast Results
Upload your GPX and get predictions in seconds.
Physics-Based Accuracy
Same core physics modeling used by premium tools.
Limitations and Accuracy Notes
While our physics model is comprehensive, real-world cycling has variables that no calculator can perfectly predict:
What We Model
- • Aerodynamic drag based on CdA and speed
- • Rolling resistance on road surfaces
- • Gravity effects on climbs and descents
- • Wind speed and direction impact
- • Air density changes with elevation
- • FTP-based pacing strategies
What We Can't Model
- • Fatigue and power fade over long distances
- • Drafting benefits in group rides
- • Technical sections requiring braking
- • Road surface quality variations
- • Weather changes during the race
- • Nutrition and hydration effects
Accuracy expectation: For well-paced solo efforts in stable conditions, expect predictions within ±3-5% of actual race times. Accuracy improves when you input precise values for your FTP, weight, and CdA.