Half Marathon Calculator
Calculate your half marathon pace, predict your finish time from shorter races, generate mile-by-mile splits, and estimate calories burned over 13.1 miles.
Half Marathon Pace Calculator
Enter your target finish time to find your required pace
Your Required Pace
--:--
per mile
--:--
per km
Half Marathon Facts
A half marathon is exactly 13.1094 miles or 21.0975 kilometers. It is precisely half of the full marathon distance of 42.195 km, which was standardized at the 1908 London Olympics.
The half marathon is the most popular long distance race in the world. In the United States alone, over 2 million runners complete a half marathon each year. It has surpassed the full marathon in total finishers since 2003.
The world record for the half marathon is 57:30 for men (Jacob Kiplimo, 2021) and 1:02:52 for women (Letesenbet Gidey, 2021). Both records were set in Valencia, Spain, known for its fast, flat course.
Most training plans for a half marathon range from 10 to 14 weeks. Beginners should be able to comfortably run 3 to 4 miles before starting a plan. The longest training run is typically 10 to 12 miles, done 2 to 3 weeks before race day.
Average Half Marathon Times by Age
Based on aggregated race result data from major half marathons across the United States.
How to Use This Half Marathon Calculator
This calculator is designed to be the only half marathon tool you need. It combines five essential calculators into one page. The Pace tab converts any target finish time into the per mile and per kilometer pace you will need to maintain. The Time tab works in reverse, showing you what finish time a given pace produces over 13.1 miles.
The Predict tab uses the Riegel and Cameron formulas to estimate your half marathon potential based on a recent 5K or 10K race result. These formulas account for the aerobic demands that increase as distance increases. A 10K prediction will generally be more reliable than a 5K prediction because 10K fitness translates more directly to half marathon performance.
The Splits tab generates an even pace split chart for all 13 miles plus the final 0.1 mile segment. Print this out or save it to your phone and tape it to your wrist on race day. The Calories tab gives you a body weight based estimate of total energy expenditure. This is helpful for planning your post race recovery meal and understanding your fueling needs.
For more detailed pace analysis, try our half marathon pace calculator. For a deep dive into split strategies, check out the half marathon split calculator. If you are working through a structured plan, see our training plans for goal time specific programs.
Train for Your Half Marathon While Capturing Territory
Half marathon training means weeks of long runs, tempo workouts, and easy miles. Motera makes every single one of those runs count by turning them into territory on a real world map. Watch your city fill in as your fitness builds toward race day.
Compete on leaderboards, earn XP for every kilometer, and explore new neighborhoods through Fog of War. Your half marathon training block becomes a strategy game.
MoteraFrequently Asked Questions
How long does it take to run a half marathon?
The average half marathon finish time is roughly 2 hours and 1 minute for men and 2 hours and 12 minutes for women. Beginners typically finish between 2:15 and 2:45. Competitive club runners aim for sub 1:30 to 1:45. Elite runners finish under 1:05 for men and under 1:10 for women.
What pace do I need to run a sub 2 hour half marathon?
To finish a half marathon under 2 hours, you need to average approximately 9:09 per mile or 5:41 per kilometer. That means every single mile needs to be faster than 9:09. In practice, aim for 9:00 per mile to give yourself a small buffer for hills, water stops, and crowded start corrals.
How do I predict my half marathon time from a 5K?
The most common method is the Riegel formula: T2 = T1 multiplied by (D2 / D1) raised to the power of 1.06. For example, a 25 minute 5K predicts roughly a 1:56 half marathon. The Cameron formula often gives a slightly faster prediction. Both methods assume consistent training at the longer distance.
How many calories does a half marathon burn?
A half marathon burns roughly 0.63 to 0.75 calories per pound of body weight per mile. A 150 pound runner burns approximately 1,400 to 1,500 calories over 13.1 miles. A 180 pound runner burns closer to 1,700 to 1,800 calories. These are estimates and actual burn depends on pace, terrain, and individual metabolism.
Should I run even splits or negative splits in a half marathon?
Negative splitting, where you run the second half slightly faster than the first, is the smartest strategy for most half marathon runners. Start 10 to 15 seconds per mile slower than your goal pace for the first 3 miles. Settle into goal pace from miles 4 through 10. Then push slightly faster for the final 5K if you feel strong.
How accurate are half marathon race predictions from shorter races?
Predictions from a recent 10K are usually accurate within 2 to 4 minutes. Predictions from a 5K tend to be optimistic by 3 to 6 minutes because the jump from 5K to half marathon is significant. The predictions assume you have trained adequately at the half marathon distance with weekly long runs of at least 10 miles.
What is the exact distance of a half marathon?
A half marathon is exactly 21.0975 kilometers or 13.1094 miles. That is precisely half of the full marathon distance of 42.195 kilometers. The distance was standardized by the IAAF (now World Athletics). When you see "13.1 miles" on a race shirt, that is a rounded approximation.
How should I fuel during a half marathon?
Most runners benefit from taking a gel or energy chew around mile 5 and again around mile 9. If you finish in under 1:30, you may not need any fuel beyond water and electrolytes. For runners finishing in 2 hours or more, plan on 30 to 60 grams of carbohydrates per hour. Practice your fueling strategy on long training runs.
