Find a Long Run Range That Fits Your Training
Stop defaulting to tradition. This calculator estimates a practical upper range for long runs based on weekly mileage and pace.
✓ Designed to avoid unnecessary fatigue at longer durations
✓ Free, no signup required
Recommended Longest Long Run
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Expected time: -
Long Run % of Weekly Mileage
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≤30% Elevated
30–35% Overreaching
35%+
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When long runs exceed ~35–40% of weekly mileage, fatigue accumulates faster than most runners recover from weekly.
Long runs at this percentage should not be repeated weekly. Consider alternating with shorter long runs or building base mileage first.
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For 16+ mile long runs, most runners need 45–50 mpw to support the recovery demands. Build weekly mileage first-chasing distance without the base is how injuries happen.
What this means
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📋 Free: Long Run Cheat Sheet
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This calculator evaluates long-run stress; it does not replace a training plan or coach. Higher percentages reflect higher recovery costs. Plans provide structure-this tool provides context. Use both intelligently.
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How This Calculator Works
Use your average from the last 6-8 weeks - not your peak week or what you hope to run.
Marathon training needs longer runs than 10K training. The calculator adjusts accordingly.
The colored bar shows how demanding your long run is relative to your weekly volume. Green is sustainable; yellow and red need more recovery.
The calculator uses the 20-30% rule: your long run should be 20-30% of weekly mileage, with adjustments for experience level and race goals. Read the full methodology →