Running Calculator - Free Online Pace and Race Time Calculator
Running Inputs
Hours
Minutes
Seconds
For calorie calculation (default: 70 kg)
For recovery time estimation
Quick Tips:
Enter your run data to calculate pace, predict race times, and get personalized training recommendations.
Enter your running data and click "Calculate" to see your stats, pace, race predictions, and training recommendations
Understanding Running Pace
Running pace is the time it takes to cover a specific distance, typically expressed as minutes per kilometer (min/km) or minutes per mile (min/mi). Understanding and managing your pace is fundamental to successful running training and racing.
Pace is more intuitive than speed for runners because it directly relates to how you experience effort during a run. A 5:00 min/km pace means you take 5 minutes to complete each kilometer. This measurement helps you plan your runs, maintain consistent effort, and achieve your race goals.
Key Pace Concepts
- • Target Pace: The pace you aim to maintain during a race or workout
- • Current Pace: Your actual pace during a run (shown on watches/apps)
- • Average Pace: Total time divided by total distance
- • Split Pace: Pace for each segment (e.g., per kilometer or mile)
Race Time Predictions
Our calculator uses the Riegel formula, a widely-accepted method for predicting race times based on a recent performance. The formula accounts for the fatigue factor that increases with distance.
📊 How Race Predictions Work
The Riegel formula: T2 = T1 × (D2 / D1)^1.06
- • T2 = Predicted time for target distance
- • T1 = Your known time
- • D2 = Target distance
- • D1 = Known distance
- • 1.06 = Fatigue factor
| Distance | Beginner | Intermediate | Advanced | Elite |
|---|---|---|---|---|
| 5K | 30-40 min | 22-30 min | 18-22 min | <15 min |
| 10K | 60-80 min | 45-60 min | 37-45 min | <30 min |
| Half Marathon | 2:15-3:00 | 1:45-2:15 | 1:20-1:45 | <1:05 |
| Marathon | 4:30-6:00 | 3:30-4:30 | 2:50-3:30 | <2:20 |
Training Pace Zones
Different training paces target specific physiological adaptations. Following the Jack Daniels' Running Formula, here are the key training zones:
🟢 Easy Pace (120% of race pace)
Purpose: Builds aerobic base, promotes recovery
- • 65-75% max heart rate
- • Conversational pace
- • 70-80% of weekly mileage
- • Essential for endurance development
🟡 Tempo Pace (95% of race pace)
Purpose: Improves lactate threshold
- • 80-85% max heart rate
- • Comfortably hard effort
- • Sustainable for 20-40 minutes
- • Once per week maximum
🟠 Interval Pace (85% of race pace)
Purpose: Boosts VO2 max and speed
- • 90-95% max heart rate
- • Hard efforts with recovery
- • 3-5 minute intervals typical
- • Equal recovery between intervals
🔵 Long Run Pace (115% of race pace)
Purpose: Builds endurance and mental toughness
- • 70-75% max heart rate
- • Slightly slower than easy pace
- • Duration: 90-180 minutes
- • Mimics race day fatigue
Frequently Asked Questions
How do I calculate my running pace?
Running pace is calculated by dividing your total time by distance. The formula is: Pace = Time / Distance. For example, if you run 10 km in 50 minutes, your pace is 50 / 10 = 5 minutes per kilometer (5:00 min/km). Pace can be expressed in minutes per kilometer (min/km) or minutes per mile (min/mi). To convert between units: 1 km pace × 1.60934 = 1 mile pace. Our calculator automatically converts between both units and provides instant results for any distance.
How accurate are race time predictions?
Race time predictions use the Riegel formula, which is approximately 90-95% accurate for most runners. The formula accounts for the fatigue factor in longer distances. Accuracy depends on your current fitness level, training consistency, race day conditions, and course terrain. Predictions are most accurate when based on a recent race performance at a similar effort level. For best results, use a time from a race completed within the last 4-6 weeks, ensure proper training for the target distance, and adjust for course difficulty and weather conditions.
What are the different training pace zones?
Training paces are based on Jack Daniels running formula. Easy runs (120% of race pace) build aerobic base and aid recovery. Tempo runs (95% of race pace) improve lactate threshold and stamina. Interval training (85% of race pace) boosts VO2 max and speed. Long runs (115% of race pace) build endurance for marathon distances. Each pace zone targets specific physiological adaptations. Easy runs should feel comfortable and conversational. Tempo runs are comfortably hard and sustainable for 20-40 minutes. Intervals are hard efforts with recovery periods.
How many calories do I burn while running?
Calorie burn during running depends on weight, pace, and distance. The calculation uses Metabolic Equivalent of Task (MET) values: running at 8 km/h burns 8.0 MET, 10 km/h burns 9.8 MET, 12 km/h burns 11.0 MET, and faster paces burn 12.3+ MET. Formula: Calories = MET × weight (kg) × time (hours). A 70 kg person running 10 km at 5:00 min/km pace (12 km/h) for 50 minutes burns approximately 572 calories. Actual burn varies with running efficiency, terrain, and fitness level.
How long should I rest after a long run?
Recovery time depends on distance and intensity. General guideline: 1 day rest per mile raced or hard run. After a 5K, rest 1-2 days. After a 10K, rest 2-3 days. After a half marathon, rest 5-7 days before hard training. After a marathon, rest 2-3 weeks before intense workouts. Easy runs can resume sooner. Listen to your body - signs you need more rest include persistent fatigue, elevated resting heart rate, decreased performance, and muscle soreness lasting over 48 hours. Adequate recovery prevents injury and allows for training adaptations.
External Resources & Further Reading
For more information about running training, pace calculation, and performance improvement, explore these trusted resources:
Runner's World - Training Guides
Comprehensive training plans, pace guides, and running tips from the world's leading running magazine.
runnersworld.com →American College of Sports Medicine
Evidence-based guidelines for physical activity and exercise training from leading sports medicine professionals.
acsm.org →American Heart Association - Fitness Basics
Physical activity recommendations and cardiovascular health guidelines for runners and athletes.
heart.org →NIH - Running Performance Research
Scientific research on running biomechanics, training adaptations, and performance optimization.
ncbi.nlm.nih.gov →