Half Marathon Pace Calculator

Calculate your target pace and split times for a half marathon (13.1 miles/21.1 kilometers). This calculator helps you plan your race strategy and achieve your time goals.

What is a Half Marathon?

A half marathon is a road running event of 13.1094 miles (21.0975 kilometers). It’s one of the most popular racing distances, offering a challenging but achievable goal for many runners.

How to Use This Calculator

1. Enter your target finish time:
   • Hours (0-23)
   • Minutes (0-59)
   • Seconds (0-59)
2. Choose your preferred distance unit (miles or kilometers)
3. Click “Calculate Pace” to see your results

Understanding the Results

The calculator provides three key pieces of information:

1. Total Time: Your target finish time
2. Pace per Mile: Your required pace per mile
3. Pace per KM: Your required pace per kilometer
4. Split Times: Detailed breakdown of your target times at each mile/kilometer

Race Pacing Strategies

Even Pacing

• Maintain the same pace throughout
• Best for experienced runners
• Most efficient use of energy
• Requires good pace awareness

Negative Split

• Run second half faster than first
• Conservative start
• Helps avoid burnout
• Popular among elite runners

Positive Split

• Start faster, slow down later
• Not recommended for most runners
• Can lead to significant slowdown
• Higher risk of “hitting the wall”

Training Tips

1. Practice Your Target Pace

   • Do training runs at race pace
   • Use a GPS watch or phone app
   • Practice on similar terrain

2. Build Endurance

   • Gradually increase long run distance
   • Include tempo runs
   • Cross-train for strength

3. Race Day Preparation

   • Study the course profile
   • Check weather conditions
   • Adjust pace for hills/weather
   • Plan hydration stops

Common Pacing Mistakes

1. Starting Too Fast

   • Excitement leads to quick start
   • Harder to recover
   • Affects overall performance

2. Irregular Pacing

   • Inconsistent energy usage
   • Mental fatigue
   • Physical strain

3. Not Adjusting for Conditions

   • Weather impact
   • Course elevation
   • Crowd factors

Using Split Times

Split times help you:

• Track progress during race
• Maintain target pace
• Adjust strategy if needed
• Stay motivated with mini-goals

Tips for Race Day Success

1. Pre-Race

   • Write split times on your arm/wrist
   • Position yourself appropriately at start
   • Warm up properly
   • Check your timing device

2. During Race

   • Check splits at markers
   • Stay focused on your pace
   • Don’t get caught up with others
   • Adjust for course conditions

3. Course Management

   • Save energy on uphills
   • Make up time on downhills
   • Account for turns and terrain
   • Plan for water stations

Frequently Asked Questions

How accurate should I follow the pace?

Allow for 5-10 seconds variation per mile/km, especially on varying terrain.

Should I use mile or kilometer splits?

Choose what you’re most comfortable with and what matches the race markers.

How do weather conditions affect pace?

Adjust your target time by 3-5% in hot/humid conditions or strong winds.

What if I fall behind pace?

Don’t try to make up time too quickly. Gradually adjust if you’re feeling strong.

Additional Resources

• Join local running groups
• Use running apps for training
• Consider a running coach
• Practice with pace groups

Remember: This calculator provides target paces, but listen to your body during the race and adjust as needed. Success in a half marathon comes from proper training, smart pacing, and race day execution.