Pace Calculator — Free Online Running Pace Tool

How to Use the Pace Calculator

1. Select your unit system: Use the toggle to choose between Metric (kilometers) and Imperial (miles). This affects the custom distance field and determines whether you primarily see km or mile-based units. Both pace units (min/km and min/mi) are always displayed regardless of your selection.
2. Choose a race distance: Select a preset distance from the dropdown menu. Options include 5K, 10K, half marathon (21.1 km), marathon (42.2 km), and several other common distances. If your distance is not listed, select "Custom Distance" and type the exact distance in the field that appears.
3. Enter your time: Fill in the hours, minutes, and seconds fields with your finish time or goal time. For example, if you finished a 10K in 55 minutes and 30 seconds, enter 0 hours, 55 minutes, and 30 seconds. The calculator updates results instantly as you type.
4. Review your results: The results panel shows your pace in both minutes per kilometer and minutes per mile, your speed in both km/h and mph, and your total finish time. Use the pace figures to set targets during training and the speed figures for treadmill settings.

You can quickly compare paces for different distances by changing the race preset while keeping the same time. This helps you understand how much faster you need to run per kilometer to achieve the same finish time at a longer distance.

Pace Formula and Calculation Method

Variables Explained

• Total Time: The total elapsed time in minutes. Converted from the hours, minutes, and seconds inputs. For example, 1 hour 23 minutes 45 seconds = 83.75 minutes.
• Distance: The total distance covered, measured in kilometers. If you enter a distance in miles, it is converted by multiplying by 1.60934. Standard race distances: 5K = 5 km, 10K = 10 km, Half Marathon = 21.0975 km, Marathon = 42.195 km.
• Pace per mile: Derived by multiplying the pace per km by 1.60934. Because a mile is longer than a kilometer, the pace per mile is always a larger number (slower-seeming) than pace per km.
• Finish Time: Calculated by multiplying the pace (min/km) by the total distance (km). This gives the total time in minutes, which is then converted to hours, minutes, and seconds for display.

Step-by-Step Calculation Example

Suppose you ran a 10K race in 50 minutes and 0 seconds:

1. Total time in minutes: 50.0 minutes
2. Distance: 10 km
3. Pace per km: 50.0 / 10 = 5:00 min/km
4. Pace per mile: 5.0 x 1.60934 = 8:03 min/mi
5. Speed: 10 / (50 / 60) = 12.0 km/h
6. Speed in mph: 12.0 / 1.60934 = 7.46 mph

At this pace, a 5K would take 25:00, a half marathon would take approximately 1:45:29, and a marathon would take approximately 3:30:58, assuming you could maintain the same pace throughout.

Practical Examples

Example 1: Rachel Training for a Sub-25 5K

Rachel is a 26-year-old runner with a current 5K personal best of 27:30. She wants to break 25 minutes at her next race. Using the calculator with 5K and a target time of 24:59:

• Required pace: 4:60 min/km (approximately 5:00 min/km) = 8:03 min/mi
• Speed: 12.0 km/h (7.46 mph)
• Current pace (27:30): 5:30 min/km
• Improvement needed: 30 seconds per km faster

Rachel sets her interval training pace at 4:45 min/km and her tempo runs at 5:00 min/km. She uses the target heart rate calculator to verify she is training in the correct intensity zones.

Example 2: David Planning His First Marathon

David is a 38-year-old runner who has completed several 10K races at around 52 minutes. He is training for his first marathon and wants a realistic goal time. His 10K pace is 5:12 min/km:

• Estimated marathon pace (add 30-60 sec/km for first-timers): approximately 5:50 min/km
• Predicted marathon finish: 42.195 km x 5:50 = approximately 4:06:00
• Target: sub-4:15 marathon (6:03 min/km pace)

David enters his marathon goal time of 4:15:00 into the calculator and sees he needs to average 6:03 min/km. He builds his long runs around a pace of 6:20-6:40 min/km and practices race pace during tempo runs.

Example 3: Linda Using Pace for Treadmill Workouts

Linda is a 45-year-old who prefers treadmill running and needs to convert her outdoor pace to treadmill speed settings. She runs 5K outdoors in about 35 minutes:

• Outdoor pace: 35 / 5 = 7:00 min/km = 11:16 min/mi
• Speed: 8.57 km/h = 5.33 mph
• Treadmill setting: 8.5 km/h or 5.3 mph

Linda sets her treadmill to 8.5 km/h for easy runs and increases to 9.5-10.0 km/h for tempo intervals. The speed display from the calculator translates directly to treadmill settings.

Common Race Distances Reference Table

Tips and Complete Guide to Running Pace

Understanding Training Paces

Effective distance training involves running at different paces for different purposes. Your easy or recovery pace should be 60 to 90 seconds per km slower than your race pace — this is where most of your weekly mileage should be. Tempo pace is roughly your pace for a race lasting 50 to 60 minutes (often close to 10K pace). Interval pace is faster than race pace and used for short, repeated efforts of 400m to 1600m. Long run pace sits between easy pace and race pace. Using a variety of paces develops different physiological systems and leads to more complete fitness.

Pacing Strategy for Races

The most common pacing mistake is starting too fast. Adrenaline, crowds, and the energy of race day make the first kilometer feel easy, but going out 20 to 30 seconds faster than target pace often leads to significant slowdown in the second half. The best strategy for most distance events is even pacing or slightly negative splits (second half faster than the first). Use the calculator to determine your target pace before the race, and check your watch at each kilometer marker to stay on track. For hilly courses, aim for even effort rather than even pace — expect to be slower going uphill and faster going downhill.

Converting Pace to Treadmill Speed

Treadmills display speed (km/h or mph) rather than pace (min/km or min/mi). Our calculator shows both speed and pace simultaneously, making it easy to set the right treadmill speed. A quick reference: 6:00 min/km = 10.0 km/h, 5:00 min/km = 12.0 km/h, 4:00 min/km = 15.0 km/h. Note that treadmill running eliminates wind resistance and often feels slightly easier than outdoor running at the same pace, so setting a 1% incline roughly compensates for this difference.

Common Mistakes to Avoid

• Running every workout at race pace: Most training should be done at easy pace (60-80% of weekly mileage). Running too fast too often leads to overtraining and injury. Hard efforts should make up only 20% of your training volume.
• Ignoring conditions when comparing paces: A 5:30 min/km pace in heat and humidity represents a significantly harder effort than the same pace on a cool day. Use perceived effort or heart rate alongside pace to account for conditions.
• Expecting linear improvement: Beginner runners often see rapid pace improvements, but progress becomes slower as fitness develops. A 30-second per km improvement over 6 months is excellent for an intermediate runner.
• Using short-distance pace to predict long races: Your 5K pace cannot be maintained for a marathon. Expect to add approximately 15-30 seconds per km for each doubling of race distance. Use race-specific pace predictions from a training pace table rather than extrapolating directly.
• Neglecting warm-up pace: Starting a run or race at target pace without warming up increases injury risk and can feel disproportionately hard. Begin 30-60 seconds slower than target pace and settle into your planned pace after the first kilometer.

Frequently Asked Questions