Marathon Training Calculator
Plan your marathon training with personalized weekly mileage targets, pace zones, and training schedule recommendations. Whether you're a first-time marathoner or an experienced runner chasing a PR, this calculator provides customized training metrics based on your current fitness, available training time, and goal finish time. Get specific pace targets for easy runs, tempo workouts, intervals, and race day.
How many miles do you currently run per week?
Number of weeks until your marathon
How many days per week can you train?
How many weeks do I need to train for a marathon?
Most marathon training plans range from 12-20 weeks depending on your experience level and current fitness. Beginners typically need 16-20 weeks to safely build up mileage and endurance, while intermediate runners can train effectively in 12-16 weeks. Advanced runners with a solid base may use 12-14 week plans. The key is having a base of 15-20 miles per week before starting your formal training plan.
What is the ideal weekly mileage for marathon training?
Weekly mileage varies by experience level. Beginners should peak at 35-45 miles per week, intermediate runners at 45-55 miles, and advanced runners at 55-70+ miles. Build gradually following the 10% rule—increase total weekly mileage by no more than 10% each week. Your long run should be 25-30% of your weekly mileage. Include a cutback week every 3-4 weeks, reducing mileage by 20-30% for recovery.
What are the different training paces and why are they important?
Training paces serve different purposes: Easy pace (1-2 min/mile slower than race pace) builds aerobic base and recovery. Tempo pace (15-30 sec/mile faster) improves lactate threshold. Interval pace (30-45 sec/mile faster) develops speed and VO2 max. Long runs at easy pace build endurance. Race pace runs help you practice goal pace. Using varied paces prevents injury and maximizes fitness gains across different energy systems.
How do I know if my marathon goal time is realistic?
A realistic goal is based on recent race times and current fitness. A common predictor: multiply your half marathon time by 2.1-2.2. For example, a 1:50 half marathon suggests a 3:50-4:00 marathon. Your training paces should feel sustainable—easy runs should be conversational, tempo runs comfortably hard, and intervals challenging but repeatable. If training paces seem impossible, adjust your goal time. First-time marathoners should focus on finishing comfortably.
What should my weekly training schedule look like?
A typical marathon week includes: 1 long run (progressively building to 18-22 miles), 1 speed/interval session, 1 tempo run, 2-3 easy runs, and 1-2 rest or cross-training days. Beginners might do 4-5 runs weekly with more rest days. Advanced runners may run 6-7 days with doubles. Always include at least one full rest day. Schedule hard workouts (long run, tempo, intervals) with easy days or rest between them to allow recovery.