Half Marathon Pace Calculator
Training for a Half Marathon? Get your splits and target pace instantly. Whether you want to break 2 hours or 90 minutes, we have the math covered.
Specialized Versions
Scientific Methodology & Accuracy
Our tools are built using peer-reviewed research and industry-standard formulas. This specific calculator utilizes PACE CALCULATOR metrics validated by sports science organizations like the ACSM and NSCA.
The concept of 'Critical Power' serves as a more stable anchor for training than the traditional FTP.
Performance Concept
"Precision metrics are the secret weapon of the world's most successful endurance athletes."
Expert Protocol
"Supplementation should only be considered once your base nutrition and sleep are optimized. Individual physiology varies. Use these results as a baseline and adjust based on your personal feel."
Embed This Tool
<iframe src="https://winsportsus.com/tools/running/half-marathon-pace-calculator" width="100%" height="800" frameborder="0" style="border-radius: 12px; box-shadow: 0 4px 6px rgba(0,0,0,0.1);"></iframe> <div style="font-size: 12px; color: #888; margin-top: 8px; text-align: center;">Powered by <a href="https://winsportsus.com/tools/running/half-marathon-pace-calculator" target="_blank" style="color: #F43F5E; text-decoration: none;">WinSportsLab</a> </div>
Want to add this calculator to your own website? Simply copy the code above and paste it into your HTML. It's free!
How to Use This Tool
- 1
Enter your goal race distance and target finish time into the Half Marathon Pace Calculator.
- 2
Review the calculated pace per kilometer and per mile to confirm it aligns with your current training capacity.
- 3
Cross-reference with your recent long run pace. If the target is 15+ sec/km faster, build gradually over 8–12 weeks.
- 4
During your next marathon-pace (MP) workout, use this pace to build neuromuscular memory for race day execution.
Key Terminology
Frequently Asked Questions
Q1 What pace do I need to run a sub-3 hour marathon?
Q2 How does temperature affect my running pace?
Q3 What is the 10% rule for increasing mileage?
Q4 What is negative splitting and why does it matter?
The Half Marathon: Physiology and Strategy
The Half Marathon (21.1 km / 13.1 miles) is the fastest-growing race distance globally, and for good reason: it sits at the intersection of speed and endurance. Unlike the 5K or 10K, which are predominantly aerobic/glycolytic efforts at near-VO2 Max intensity, the half marathon is raced at or slightly below the lactate threshold — the highest intensity at which lactate clearance keeps pace with production.
This means race pace feels "comfortably hard" — you can technically speak a few words but sustaining a conversation is impossible. It's the same intensity you'd hold for an all-out 1-hour effort.
Half Marathon Pace Chart
| Goal Time | Pace (min/km) | Pace (min/mile) | 5K Equivalent | |-----------|--------------|----------------|--------------| | Sub 1:25 | 4:02 | 6:29 | ~19:00 | | Sub 1:30 | 4:16 | 6:52 | ~20:00 | | Sub 1:45 | 4:58 | 7:59 | ~23:00 | | Sub 2:00 | 5:41 | 9:09 | ~26:30 | | Sub 2:15 | 6:24 | 10:18 | ~29:30 |
Key Training Runs for the Half Marathon
1. Threshold Runs (Weekly) 30–40 minutes at half marathon goal pace, or slightly faster. Raises your lactate threshold — the primary limiter at this distance. Example: 3×10 minutes at HM pace, 2-minute jog recovery.
2. Long Runs (Weekly) Build to 19–22 km (12–14 miles) at easy pace (60–75 seconds per km slower than goal pace). This develops aerobic base and fat oxidation capacity without excessive recovery demand.
3. Race-Pace Miles (Bi-Weekly) 4–6 × 1 mile at exact goal half marathon pace. Builds the muscular and metabolic memory of holding your goal effort.
*Source: Pfitzinger, P. & Douglas, S. (2016). Road Racing for Serious Runners. Human Kinetics.*
Pacing Strategy on Race Day
Research on pacing in recreational half marathons (Renfree & Gibson, 2013, *International Journal of Sports Physiology and Performance*) consistently shows that even splits or slight negative splits produce the fastest times. Going out 5–10 seconds/km too fast in the first 5 km nearly always results in a degraded final 5 km, eroding the early "time bank."
Recommended approach: First 5km at 3–5 seconds/km *slower* than goal pace. Settle into goal pace from km 5–16. Use the final 5 km to run by feel — if you still have energy, this is where you can make time.
Use Cases / Example Scenarios
Apply the output to find your lactate threshold pace and design progressive tempo sessions that build sustainable speed.
Input your goal finish time to calculate the exact fueling schedule (km 7, 14, 21, 28, 35) needed to avoid glycogen depletion.
When ambient temperature exceeds 15°C, use the calculated pace to apply a 60-sec/hour slowdown for realistic warm-weather goal-setting.
Enter your recent 5K or 10K result to project a realistic marathon or half marathon finish time using the Daniels VDOT method.
Confirm your target pace hasn't drifted during a 3-week taper by running a controlled 5km at goal pace with heart rate monitoring.
Related Tools
View All Tools →Marathon in 4h 15m for 20s Men: Pace & Age-Adjusted Plan
Physiology-backed Marathon pacing guide for male runners ages 20-29. Includes age-graded HR zones, injury risk profile, and a 4h 15m training blueprint.
Is a 315 lb Squat Good for a 200 lb woman?
Find out what a 315 lb Squat means for someone weighing 200 lbs. Includes strength level, percentile, and training tips.
Is a 315 lb Squat Good for a 205 lb man?
Find out what a 315 lb Squat means for someone weighing 205 lbs. Includes strength level, percentile, and training tips.
Is a 315 lb Squat Good for a 205 lb woman?
Find out what a 315 lb Squat means for someone weighing 205 lbs. Includes strength level, percentile, and training tips.