Altitude Running Calculator
Convert running pace between altitudes using VO2max reduction models. Understand how elevation affects your performance with adjustments for acclimation, event type, and altitude native status.
Convert Running Pace Between Altitudes
Account for VO2max changes at elevation
Enter your sea level (reference) pace to see what pace to run at altitude for the same effort.
Altitude Settings
Usually sea level (0-300m)
Altitude natives have physiological advantages
Sea Level Pace
5:00
min/km
@ 0m
Altitude Pace
5:17
min/km
@ 1800m
Speed Change
-5.2%
slower at altitude
Finish Time Comparison
At Sea Level (0m)
25:00
At Altitude (1800m)
26:23
Time difference: +5.5% (+1:23 slower)
VO2max Change
-12.6%
Event Type
Middle
Acclimation
Not
Altitude Native
No
How this works: VO2max decreases approximately 7% per 1000m of elevation gain (Wehrlin & Hallen research). However, performance impact is moderated by race duration—short events (1500m-3k) are most affected, while easy runs see minimal change. Acclimation over 3+ weeks can reduce the impact by about half.
Note: This is an evidence-informed estimate based on average responses. Individual variation is significant. Heat, humidity, and course profile can have as much or more impact than altitude alone. For very high altitudes or if you feel unwell (headache, dizziness), prioritize safety over pace goals.
About the Altitude Running Pace Converter
Learn more about the calculator and its creator
Jonas
I have been a runner for over 10 years and I built this calculator to help runners like you and me with training and racing.
The Science of Altitude and Running Performance
Altitude significantly impacts running performance by reducing the oxygen available to working muscles. This calculator uses research-based VO2max reduction models to predict how elevation affects your pace.
Key Research: VO2max Drop with Altitude
Several studies have quantified VO2max reduction at altitude for sea level residents:
- Wehrlin & Hallen: VO2max dropped ~6.3% per 1000m between 300m and 2800m in elite endurance athletes
- Physio-pedia summary: VO2max decreases 8-11% for every 1000m ascent
- Girard et al. position statement: ~7% per 1000m decline in maximal aerobic power
- Runners World chamber studies: ~6.8% VO2max drop at only 580m in lab tests
Our model uses 7% per 1000m as the base coefficient, which sits in the middle of these estimates for trained, non-acclimated athletes.
Why Performance Drop < VO2max Drop
Race data shows smaller performance changes than raw VO2max drops:
- Olympic/World Championship data: 2-4% slower endurance events above ~1000m
- NCAA altitude tables: ~3% slower 5k at Denver (~1600m) vs sea level
- Coaching rules: ~4-5 seconds per mile slower per 1000ft above 3000ft for threshold pace
The gap exists because athletes don't use 100% of VO2max during most races, and running economy moderates the effect.
The Core Model
Step 1: VO2max Change with Altitude
k_vo2_base = 0.07 (7% per 1000m)
Δh = (current_alt - ref_alt) / 1000 // in km
r_VO2 = 1 - k_vo2_eff × Δh
Step 2: Acclimation Factor (F_accl)
- Not acclimated (<5 days): F_accl = 1.0 (full effect)
- Partial (5-21 days): F_accl = 0.7
- Fully acclimated (>3 weeks): F_accl = 0.5
- If altitude native: multiply by additional 0.7
k_vo2_eff = k_vo2_base × F_accl
Step 3: VO2max to Speed Conversion (α exponent)
- Short endurance (1500-3k): α = 0.5
- 5k-10k: α = 0.4
- Half-marathon+: α = 0.3
- Threshold pace: α = 0.3
- Easy runs: α = 0.15
r_speed = r_VO2α
Step 4: Pace Conversion
Effort mode: p_alt = p_sea / r_speed
Pace mode: p_sea = p_alt × r_speed
Event Type Exponents Explained
The exponent (α) reflects how much VO2max changes translate to speed changes for each event type:
| Event Type | α | Rationale |
|---|---|---|
| 1500m-3k | 0.5 | Runs closest to VO2max, most affected |
| 5k-10k | 0.4 | High VO2max utilization |
| Half-Marathon+ | 0.3 | Lower % of VO2max, moderate effect |
| Threshold Pace | 0.3 | Similar to long distance racing |
| Easy Runs | 0.15 | ~60% VO2max, barely affected |
Example Calculation
Scenario: 10k race at 1800m, non-acclimated sea level resident
- Δh = 1800 / 1000 = 1.8 km
- k_vo2_eff = 0.07 × 1.0 (not acclimated) = 0.07
- r_VO2 = 1 - 0.07 × 1.8 = 0.874 (~12.6% VO2max drop)
- α = 0.4 (10k event)
- r_speed = 0.8740.4 = 0.946 (~5.4% speed drop)
- If sea level 10k = 40:00 (4:00/km) → Altitude 10k ≈ 42:18 (4:14/km)
Acclimation and Altitude Natives
Long-term acclimatization can partially preserve VO2max and performance:
| Status | Factor | Effect |
|---|---|---|
| Not acclimated (<5 days) | 1.0 | Full altitude effect |
| Partial (5-21 days) | 0.7 | ~30% reduction in effect |
| Full (>3 weeks) | 0.5 | ~50% reduction in effect |
| Altitude native (additional) | ×0.7 | Stacks with acclimation |
Mountain guides and high-altitude natives show smaller VO2max declines at moderate altitude compared to lowlanders. "Live high, train low" protocols over 3+ weeks can improve performance without fully preventing VO2max loss.
Validation Against Real Race Data
Our model produces results consistent with:
- At 1000m, non-acclimated, 10k: ~2-3% slowdown (model: ~2.5%)
- At 2000m, non-acclimated, 10k: ~4-6% slowdown (model: ~5%)
- NCAA Denver 5k adjustment: ~3% slower (model: ~3.2% at 1600m)
Altitude Zones
| Altitude | Category | Notes |
|---|---|---|
| 0-1000m | Low | Minimal effect (~1-2%) |
| 1000-2500m | Moderate | Noticeable effect (2-6%) |
| 2500-3500m | High | Significant effect (6-10%+) |
| >3500m | Very High | Health risks, predictions less reliable |
How This Differs from Simple Altitude Calculators
- Starts from VO2max reduction per 1000m from controlled lab studies
- Calibrates to real race data (Olympics, NCAA, championship events)
- Differentiates by event type (short races vs marathons vs easy runs)
- Accounts for acclimation status and altitude native advantages
- Uses transparent math that can evolve with new research
Limitations and Caveats
- This is an evidence-informed estimate based on average responses—individual variation is large
- Heat, humidity, and course profile can have as much impact as altitude
- Above 3500m, health risks become more important than pace predictions
- For very high altitudes, prioritize proper acclimatization over performance
Important: If you feel unwell at altitude (headache, dizziness, nausea), safety is far more important than pace. Descend or rest if you experience altitude sickness symptoms.
Related Tools & Guides
Altitude Pace Chart
Pace adjustment tables by altitude
How Altitude Affects Running
The science of elevation and performance
Altitude Acclimation Guide
How to prepare for altitude racing
Running Heat Calculator
Heat-adjusted pace predictions
Running Humidity Calculator
Dew point pace adjustments
Jack Daniels Calculator
VDOT and training paces
Frequently Asked Questions
VO2max decreases approximately 7% per 1000m of elevation gain. However, performance impact is less than VO2max drop—typically 2-4% slower race times at 1500-2000m for 5k-10k distances. Easy runs are barely affected.
Short races (1500m-3k) run closer to VO2max, so they feel altitude's impact more directly. Marathons run at a lower percentage of VO2max, so the reduction matters less. Easy runs at ~60% VO2max barely change pace at altitude.
Partial adaptation occurs in 5-21 days, with approximately 30% reduction in performance penalty. Full acclimation at 3+ weeks can reduce the impact by about 50%. Altitude natives (grew up above 1800m) have additional advantages.
Moderate altitude (1500-2500m) produces noticeable effects. High altitude (2500-3500m) significantly impacts performance. Above 3500m, health risks increase substantially and predictions become less reliable.
Barely. Easy running (~60% VO2max) is minimally affected by altitude—perhaps 1-2% slower even at 2000m. Run by effort/heart rate rather than pace for easy runs at altitude.
Effort Mode: Enter your sea level pace and see what pace to run at altitude for equivalent effort. Pace Mode: Enter a pace you ran at altitude and see what it equals at sea level (your 'true' fitness level).
Yes. Runners who grew up above ~1800m have physiological adaptations (higher hemoglobin, better oxygen extraction) that reduce the performance penalty when racing at altitude. Our calculator includes a factor for this.
NCAA tables show roughly 3% slower 5k times at Denver (~1600m). Our model produces similar results for non-acclimated runners at middle distances, validating the ~7% VO2max/1000m coefficient.
Yes, 'live high, train low' protocols over 3+ weeks can improve sea level performance through increased red blood cell production. However, this is separate from predicting race performance at altitude.
The model is based on Wehrlin & Hallen research (~6.3% per 1000m), position statements (~7%), and real race data. Individual variation is significant—some runners tolerate altitude better than others. Use as a guide, not an absolute prediction.
How much does altitude affect running performance?
Why are short races more affected than marathons?
How long does altitude acclimation take?
What altitude is considered 'high altitude' for running?
Should I adjust my easy run pace at altitude?
What is the difference between Pace Mode and Effort Mode?
Do altitude natives have an advantage?
How does this compare to NCAA altitude adjustments?
Can I train at altitude to improve sea level performance?
How accurate is this calculator?
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