Running Pace Calculator
Whether you are training for a 5K or planning your first marathon, pace is the number you need to hit — and miss by a few seconds per mile and the whole plan falls apart. This free pace calculator turns any distance and time into pace per kilometer and per mile, your average speed, and exact finish times for 5K, 10K, half marathon and marathon.
Pace Calculator
How to Use This Calculator
Enter the distance you ran or plan to run and pick its unit — kilometers or miles. Then enter the time in hours, minutes and seconds. A 30-minute 5K would be 0 hours, 30 minutes and 0 seconds; a 4-hour marathon is 4, 0, 0.
Click Calculate and the tool shows your pace in the mm:ss format runners use every day — both per kilometer and per mile, so you can read either one — plus your average speed in km/h and mph. No matter which unit you entered the distance in, you get both versions.
Below the summary, the finish-time table projects that same pace across the four most common race distances: 5K, 10K, half marathon and marathon. It is the fastest way to check whether a goal time is realistic before you commit to it.
The Formula
The math is straightforward. First convert your time to seconds: totalSeconds = hours × 3600 + minutes × 60 + seconds. Pace is the time per unit of distance: pace = totalSeconds ÷ distance, in seconds per kilometer or per mile depending on the unit you chose. Speed is the distance per hour: speed = distance ÷ (totalSeconds ÷ 3600). To convert between the two pace units, remember that 1 mile = 1.609344 km.
Worked example: you run 5 km in 30:00. Total time is 0 × 3600 + 30 × 60 + 0 = 1800 seconds. Pace: 1800 ÷ 5 = 360 seconds per km, which is 6:00 per km. Per mile: 360 × 1.609 = 579 seconds, or 9:39 per mile. Speed: 5 ÷ 0.5 = 10.0 km/h, or 6.2 mph. Hold that pace and your finish times are 1:00:00 for a 10K, 2:06:35 for a half marathon and 4:13:10 for a marathon.
Tips
Race the second half, not the first. Most personal bests come from negative splits — running the second half a few seconds per mile faster than the first. The finish-time table assumes an even pace, so treat it as a best case and build in a small cushion on race day.
Find your training paces from effort, not just numbers. An easy recovery run should be roughly 90–120 seconds per mile slower than your 5K pace, and you should be able to hold a conversation. Save your goal pace for tempo runs and intervals, where it belongs.
Recheck your paces every 6–8 weeks as fitness improves. If a pace that once felt hard now feels manageable, update the calculator with a recent race or time trial — training at an outdated pace quietly limits your progress.
Frequently Asked Questions
What is a good running pace for a beginner?
A comfortable, conversational pace — typically 8:00 to 10:30 per mile (5:00 to 6:30 per kilometer) for a new runner — is a great starting point. The right pace is one where you can speak a full sentence without gasping.
How can I improve my running pace?
Run most of your miles easy, and add one or two harder sessions a week: tempo runs at a comfortably hard effort, or short intervals faster than race pace. Consistency beats intensity — most runners improve steadily over 8–12 weeks.
What's the difference between pace and speed?
Pace is the time it takes to cover a fixed distance (minutes per mile or per kilometer); speed is the distance covered per hour (miles per hour or km/h). Runners use pace for training because effort maps to time per distance, not per hour.
What pace should I aim for in a 5K?
Aim for a pace that is challenging but sustainable for 20–40 minutes, depending on your level. If you currently run 5 km in 30:00, your 6:00 per km pace is a good target — then try to shave 10–15 seconds per km in your next race.
How do I pace myself during a marathon?
Run the first 10K 10–15 seconds per mile slower than your target pace, settle into your goal pace through mile 20, then push the final 10K if you have anything left. The marathon stories about bonking are almost always runners who started too fast.