Pace Calculator

About the Pace Calculator

A pace calculator converts between running pace (minutes per mile or per kilometre), speed (miles per hour or km/h), and finish time for any race distance — from a 5K to a full marathon. Whether you are a beginner runner working out what pace to target for your first race, an experienced runner planning splits for a Boston Qualifier attempt, or a triathlete calculating run leg pace for an Ironman event, our free pace calculator gives you instant, precise answers in both metric and imperial. Enter any two of the three variables — distance, time, or pace — and the calculator finds the third. It also generates a complete split table showing your expected time at every mile or kilometre marker, and calculates the even-split pace required to finish any standard race distance in a target time. Standard race distances covered: 5K (3.107 miles), 10K (6.214 miles), half marathon (13.1 miles / 21.1 km), marathon (26.2 miles / 42.2 km), and custom distances.

How It Works

The three-variable relationship: Pace (min/mile) = Total Time (minutes) / Distance (miles). Speed (mph) = 60 / Pace (min/mile). Total Time = Pace x Distance. Example: target finish time of 1:45:00 for a half marathon (13.1 miles). Pace = 105 minutes / 13.1 miles = 8:01 per mile = 4:59 per km. Speed = 60 / 8.017 = 7.48 mph = 12.03 km/h. Split projection at 8:01/mile: Mile 1 = 8:01, Mile 5 = 40:05, Mile 10 = 1:20:10, Mile 13 = 1:44:13, finish = 1:45:00. Converting pace to speed: 8:00/mile = 60/8 = 7.5 mph. Converting km pace to mile pace: multiply km pace by 1.60934. An 5:00/km pace = 5:00 x 1.60934 = 8:03/mile.

Tips & Best Practices

• ✓Rule of thumb for race pace from training: your sustainable race pace for a given distance is approximately 10-20 seconds per mile faster than your easy training pace for shorter distances, and 60-90 seconds slower than your 5K pace for a marathon.
• ✓Negative splits strategy: running the second half of a race slightly faster than the first half is associated with better performances and less post-race fatigue. Target the first mile at 5-10 seconds per mile slower than goal pace.
• ✓Common qualifying standards: Boston Marathon qualifying times for age 18-34 are 3:00:00 (men) and 3:30:00 (women) — requiring 6:52/mile and 8:01/mile paces respectively. Use the pace calculator to work backward from any qualifying standard.
• ✓Treadmill conversion: treadmill speed is displayed in mph, not pace. 6.0 mph = 10:00/mile; 7.5 mph = 8:00/mile; 8.0 mph = 7:30/mile; 10.0 mph = 6:00/mile. The pace calculator converts instantly between the two.
• ✓Heart rate and pace: easy runs should feel conversational (you can speak in full sentences), typically 60-70% of max heart rate. Tempo runs are "comfortably hard" at 80-85%. Race pace for 5K is approximately 90-95% of max heart rate.
• ✓Elevation adjustment: for every 1% gradient uphill, add approximately 12-15 seconds per mile to your flat-road pace. A 5% hill requires roughly 60-75 seconds extra per mile.
• ✓Pace consistency matters more than average pace: two runners finishing a 5K in the same time — one with even splits, one who went out fast and faded — will have very different race experiences, with the even-splitter feeling much stronger at the finish.
• ✓Walk-run intervals for beginners: the Galloway method uses planned walk breaks of 30-60 seconds every mile or every few minutes. Calculate your effective pace including walk breaks to set realistic finish time expectations.

Who Uses This Calculator

Beginner runners training for their first 5K or 10K use the pace calculator to set realistic finish time targets and understand what pace to run in training to achieve their goal. Experienced marathoners and half marathoners plan race strategy by calculating even and negative split paces for every mile marker. Competitive runners compare their current training pace against qualifying standards for prestigious races like the Boston Marathon and use the calculator to determine how much improvement they need. Triathlon and duathlon athletes calculate run leg paces needed to achieve overall finish time goals. Running coaches create pace charts for athletes at different ability levels training together. Track and cross-country athletes convert between per-mile and per-lap paces for different track distances. Fitness app users cross-reference their GPS watch data (which shows pace) against finish time predictions.