Pace Calculator for Training Runs and Race Day

There's no single number. A good pace depends on your age, fitness, and how far you're going. For health, the CDC's activity guidelines for adults (opens in a new tab) suggest 150 minutes of moderate activity, such as brisk walking, or 75 minutes of vigorous activity, such as running, each week. To track progress, compare your own pace on the same route every few weeks.

About 9:09 per mile, or 5:41 per kilometer, held the whole way. To check another goal, leave it on Calculate pace, pick Half marathon from the race list, and enter your target time. That assumes an even pace, so any time lost at water stops or a crowded start has to be made up later.

It means running the second half of a race faster than the first. The calculator works out one even pace, so to plan a negative split, run it twice. Choose Calculate time, type half the race distance under Distance, and enter a slightly slower pace for the first half. Then change it to a faster pace for the second half, and add the two times to check you still hit your goal.

A marathon is 42.195 km, or about 26.2 miles, and a half marathon is exactly half: 21.0975 km, or about 13.1 miles. These are the official race distances (opens in a new tab) set by World Athletics. When you pick either race in the list, the calculator uses the exact length, not the rounded one.

Not with this pace calculator alone. The race rows show how long each distance takes at the pace you entered, with no slowdown built in. Almost nobody can hold their 5K pace for a full marathon, so read the marathon row as the time for that pace, not a forecast.

The math is the same, so the gap usually comes from the distance. GPS can drift on winding routes or between tall buildings. Race courses are also measured along the shortest route a runner could take (opens in a new tab), so if you swing wide on the turns, your watch logs more distance than the course and shows a slightly faster pace.

Use the pace calculator the same way: enter how far you walked and how long it took, and you'll get your pace and your speed. It handles slow and fast paces alike. It's one of the free tools on EZ Calculator, which also has a body fat calculator if you track your fitness in other ways.