Marathon Mileage Buildup
Calculator
Results
- Peak reached
- 70 kilometres
- Total distance
- 888.634307 kilometres
- Weeks to peak
- 10 wk
- Average weekly volume
- 49.368572 kilometres
Projected path over the weeks
- Weekly mileage
- Baseline weekly mileage
Week-by-week schedule
| 1 | 30.00 | 30.00 | 30.00 |
| 2 | 33.00 | 63.00 | 30.00 |
| 3 | 36.30 | 99.30 | 30.00 |
| 4 | 39.93 | 139.23 | 30.00 |
| 5 | 43.92 | 183.15 | 30.00 |
| 6 | 48.32 | 231.47 | 30.00 |
| 7 | 53.15 | 284.62 | 30.00 |
| 8 | 58.46 | 343.08 | 30.00 |
| 9 | 64.31 | 407.38 | 30.00 |
| 10 | 70.00 | 477.38 | 30.00 |
| 11 | 70.00 | 547.38 | 30.00 |
| 12 | 70.00 | 617.38 | 30.00 |
| 13 | 70.00 | 687.38 | 30.00 |
| 14 | 70.00 | 757.38 | 30.00 |
| 15 | 70.00 | 827.38 | 30.00 |
| 16 | 35.00 | 862.38 | 30.00 |
| 17 | 17.50 | 879.88 | 30.00 |
| 18 | 8.75 | 888.63 | 30.00 |
Comparison
| Scenario | Peak reached | Total distance |
|---|---|---|
| Doing nothing | 30.00 | 540.00 |
| Your plan | 70.00 | 888.63 |
Formula
mileage(w) = min(start × (1+r)^(w−1), peak); taper halves the peak weekly= 70.00
Note
These are deliberately simplified models. They assume a constant rate and ignore metabolic adaptation, water weight, hormones, illness, medication, sleep and stress, so individual results vary widely — two people following the same plan can land far apart. The 7700 kcal per kilogram of body fat figure is a population average, not a personal constant. A large deficit, a fast mileage or load ramp, or a very low target body fat can be harmful; treat any flagged rate as a reason to slow down. This is NOT medical, dietetic or coaching advice — consult a qualified doctor, registered dietitian or accredited coach before acting on any projection here, and especially if you are pregnant, under 18, or managing any medical condition.
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See all →Frequently asked questions
Why does the calculator limit how fast weekly mileage increases?+
It typically caps increases around 10% per week, a widely used guideline to limit injury risk — tendons, ligaments, and bone adapt to training load more slowly than cardiovascular fitness does, so ramping too fast outpaces the body's structural adaptation.
What are step-back or recovery weeks and why does the plan include them?+
Every third or fourth week, the plan typically reduces mileage by 20-30% instead of increasing it, giving the body time to absorb the training load — skipping these recovery weeks is a common cause of overuse injuries in marathon buildups.
How far in advance should peak weekly mileage occur before race day?+
Peak mileage typically happens 2-3 weeks before the race, followed by a taper — a progressive reduction in volume that allows the body to recover fully while maintaining fitness, so you arrive at the start line rested rather than fatigued.
What happens if I miss a few weeks of the buildup?+
Don't try to make up lost mileage by jumping back in at your previous level — resume at a lower mileage than where you left off and rebuild gradually, since fitness losses from a short break are smaller than the injury risk of resuming too aggressively.
Does the buildup plan account for long runs specifically?+
Yes — long runs typically increase separately from total weekly mileage, since they carry more of the race-specific endurance benefit, and most plans cap the longest run at a percentage of total weekly volume to avoid overloading a single session.