Pace Calculator
Calculate Pace by entering distance and time. Get pace per mile or kilometre, projected finish times, and split breakdowns.
Reviewed by Daniel Agrici, Founder & Lead Developer · Editorial policy
Pace Calculator Formula
Pace = Time / Distance
Pace is calculated by dividing total time by distance. Speed is the inverse: distance divided by time. This calculator converts between miles and kilometers and projects finish times for common race distances at your current pace.
Pace Calculator — Worked Examples
Example 1: 5K Race Time from Pace
Problem:You run at an 8:00/mile pace. What's your projected 5K time?
Solution:5K distance = 3.107 miles\nTime = 8:00/mile × 3.107 miles = 24:51\nPace per km = 8:00 / 1.609 = 4:58/km\nSpeed = 60/8 = 7.5 mph = 12.1 kph
Result:5K time: 24:51 | Pace: 4:58/km | Speed: 7.5 mph
Example 2: Marathon Pace Planning
Problem:You want to finish a marathon in 3:45:00. What pace do you need?
Solution:Total time = 3:45:00 = 13,500 seconds\nMarathon distance = 26.2188 miles\nPace = 13,500 / 26.2188 = 515.0 sec/mile = 8:35/mile\nPace per km = 515.0 / 1.609 = 320.1 sec/km = 5:20/km\nSpeed = 7.0 mph
Result:Required pace: 8:35/mile (5:20/km) | Speed: 7.0 mph
Pace Calculator — Frequently Asked Questions
What is a good running pace for beginners?
A good starting pace for beginner runners is 10-12 minutes per mile (6:15-7:30 per km). This might feel slow, but running at a conversational pace (where you can talk in complete sentences) builds your aerobic base and prevents injury. Most running coaches follow the 80/20 rule: 80% of your runs should be at an easy, conversational pace, and only 20% at higher intensity. As fitness improves, your easy pace will naturally get faster. Don't chase pace early on — chase consistency.
How do I convert between pace per mile and pace per km?
To convert pace per mile to pace per km, divide by 1.60934. For example, an 8:00/mile pace equals approximately 4:58/km. To go the other way, multiply your km pace by 1.60934. A 5:00/km pace equals approximately 8:03/mile. Pace Calculator does both conversions automatically. Remember: pace per km will always be a faster (smaller) number than pace per mile since a kilometer is shorter than a mile.
What pace do I need for a sub-4-hour marathon?
For a sub-4-hour marathon, you need to maintain a pace of 9:09 per mile or 5:41 per km. This means completing each 5K split in approximately 28:25. A good strategy is to run the first half slightly slower (negative split) — aim for a 2:02 first half and a 1:58 second half. For a sub-3:30 marathon, target 8:01/mile. For sub-3:00, target 6:52/mile. Training should include long runs, tempo runs at goal pace, and speed intervals.
What's the difference between pace and speed?
Pace is time per unit distance (minutes per mile or km) — it tells you how long it takes to cover a set distance. Speed is distance per unit time (mph or kph) — it tells you how much ground you cover in a set time. Runners typically use pace because it's more intuitive for planning: 'I need to run 8-minute miles' is easier to execute than 'I need to run 7.5 mph.' However, treadmills display speed, so knowing both is useful. A pace of 8:00/mile = 7.5 mph = 12.1 kph.