Running Pace Calculator
Calculate running pace, total time, or distance. Supports miles and kilometers, with common race distance presets.
I use the time-from-distance version most, plug in a race distance and target pace to see what finish time that produces. It's the fastest way to reality-check a race goal. A 4-hour marathon requires exactly 9:09/mile. Knowing that during training tells you whether your long runs are on pace or not.
A 4-hour marathon = 9:09/mile. A 2-hour half marathon = 9:09/mile. A 30-minute 5K = 9:39/mile. A sub-20 5K requires 6:26/mile. These are the benchmarks most recreational runners target.
Pace vs speed
Pace is time per distance unit (minutes per mile or km). Speed is distance per time unit (mph or km/h). Runners use pace; cyclists typically use speed. They're reciprocals: an 8:00/mile pace = 7.5 mph. A 5:00/km pace = 12 km/h. Converting between them is useful when a treadmill displays mph but you think in pace.
Negative splits and pacing strategy
A negative split means running the second half of a race faster than the first. Most world records are set with negative or even splits. Most beginners go out too fast and slow down dramatically. For training runs, even splits (same pace throughout) or slight negative splits teach sustainable pacing. The most common mistake in racing is starting at goal pace when you haven't trained at it consistently.
Pace zones and training
Different training runs target different paces. Easy runs should be 60–90 seconds per mile slower than race pace, genuinely conversational. Tempo runs are at lactate threshold pace, comfortably hard, sustainable for 20–40 minutes. Interval repeats target race pace or faster for short distances (400m–1 mile) with recovery jogs between. Most recreational runners do too many runs at moderate "comfortable hard" pace and not enough at true easy or true hard intensities.
Frequently asked questions
How much slower should my easy runs be?
At least 60–90 seconds per mile slower than your current 5K race pace. Many runners find this uncomfortably slow at first, it feels too easy. That feeling is often correct. True easy pace for a 25-minute 5K runner (8:03/mile pace) is around 9:30–10:00/mile. Most people train at 8:30–9:00, which is too fast for easy but not fast enough for real quality work.
How do I calculate my finish time from a target pace?
Enter the race distance, select "time" from the solve dropdown, enter your target pace, and click Calculate. The total time result is your projected finish time.