Calculator Inputs
Use the responsive layout below. It shows three columns on large screens, two on smaller screens, and one on mobile.
Example Data Table
This example shows how a balanced mid-plan block can look before the final taper begins.
| Week | Phase | Weekly Distance | Long Run | Estimated Time | Primary Focus |
|---|---|---|---|---|---|
| 6 | Foundation | 48 km | 22 km | 5h 05m | Easy aerobic volume and short strides |
| 7 | Specific Build | 54 km | 24 km | 5h 38m | Tempo session and fueling rehearsal |
| 8 | Specific Build | 58 km | 27 km | 6h 00m | Marathon-pace work inside long run |
| 9 | Recovery | 50 km | 21 km | 5h 12m | Reduced load for adaptation and freshness |
Formula Used
The calculator blends goal pace, current readiness, available training time, and recovery preferences into one timeline recommendation.
1. Goal pace
Goal Pace = Total Goal Time in Seconds ÷ 42.195
2. Time-supported peak distance
Time-Supported Peak Distance = Weekly Available Seconds ÷ Estimated Easy Pace Seconds Per Kilometer
3. Peak weekly distance target
Peak Weekly Distance = Goal-Based Mileage × Experience Factor × Training-Day Factor × Injury Factor × Cross-Training Adjustment
4. Readiness score
Readiness Score = 55% × (Current Weekly Distance ÷ Peak Weekly Distance) + 45% × (Current Long Run ÷ Peak Long Run)
5. Recommended plan length
Recommended Weeks = Base Plan Weeks + Readiness Gap Weeks, limited to a practical minimum and maximum
6. Estimated weekly training time
Estimated Time = Weekly Distance × Easy Running Pace
The weekly schedule then applies progressive overload, regular cutback weeks, a peak phase, and a final taper. The taper reduces volume while keeping enough rhythm for race-day sharpness.
How to Use This Calculator
Follow these steps to build a usable marathon timeline and then fine-tune it with your own recovery experience.
- Enter your plan start date and race date.
- Choose kilometers or miles for all distance inputs.
- Add your current weekly distance and current long run.
- Set how many hours and run days you can realistically manage each week.
- Enter your target finish time.
- Select your experience level, injury sensitivity, and cutback rhythm.
- Press the submit button to generate the timeline above the form.
- Review the chart, pace zones, weekly schedule, and export files if needed.
Frequently Asked Questions
These FAQs use plain HTML blocks and avoid accordion styling, exactly as requested.
1. How many weeks do I really need for marathon training?
Most runners benefit from 12 to 20 focused weeks. Beginners often need closer to 18 to 20 weeks, especially if current weekly mileage or long-run readiness is still low.
2. Why does the calculator use both weekly distance and long run?
Weekly distance reflects overall workload, while the long run reflects endurance readiness. Combining both gives a better estimate of how much training stress you can safely absorb.
3. What does the readiness score mean?
The readiness score is a practical indicator of how close your current training is to the plan’s peak demands. Higher scores suggest less catch-up work is required.
4. Why are cutback weeks included?
Cutback weeks reduce fatigue and give your body time to adapt. Without them, steady mileage growth can become harder to sustain and injury risk can rise.
5. Can I train for a marathon with only four run days?
Yes, many runners succeed on four run days weekly. The key is protecting the long run, keeping one quality session, and using recovery wisely.
6. Why does available weekly time affect the mileage target?
Distance requires time. A schedule that exceeds your real weekly hours quickly becomes inconsistent. Time-based limits help keep the plan realistic and repeatable.
7. Should I always follow the generated pace zones exactly?
Use them as a strong starting point, not a rigid rule. Weather, terrain, fatigue, and heart-rate response can justify slightly slower or faster training on some days.
8. Is this calculator a medical or coaching substitute?
No. It is a planning tool. If you have injury history, medical concerns, or unusual fatigue, adapt the schedule with a qualified coach or health professional.