How do I calculate my running pace?

Pace per mile or kilometer = total time ÷ distance. Enter any run's distance and finish time in the calculator's 'Find pace' tab to get your pace in minutes and seconds per mile or kilometer instantly.

How are the predicted race times calculated?

Using Riegel's formula (T2 = T1 × (D2/D1)^1.06), a widely used and well-established running-world method for estimating race performance at a new distance from a known one. It assumes a similar level of training and pacing strategy across distances, so treat the predictions as a reasonable estimate, not a guarantee — actual results vary with training, terrain, and conditions.

Why does my predicted marathon time seem slower than just scaling up my 5K pace?

Riegel's formula deliberately doesn't scale linearly — the exponent (1.06) reflects the fact that maintaining a given pace gets harder as distance increases, due to fatigue and fueling demands. This is why a straight per-mile pace multiplication would underestimate marathon time compared to the more realistic Riegel prediction.

What's a good pace for a beginner runner?

There's no single 'good' pace — it depends entirely on your fitness level, goals, and the distance you're training for. Many beginners comfortably run in the 10-13 minute per mile range and build speed over time; consistency matters far more than any specific number on the clock.

Can I use this for walking or run-walk intervals?

Yes — the distance, time, and pace formula works identically regardless of speed. Enter your walking pace or an average combined run-walk pace to get accurate time and distance estimates the same way a runner would.

Is my data stored anywhere?

No. All calculations run locally in your browser. Nothing you enter is transmitted to a server or stored.

AI Insights

Running Pace Calculator

Find your running pace, total time, or distance from any two of the three, plus predicted race times at 5K, 10K, half marathon, and marathon distances.

Last updated August 24, 2026

Distance (mi)

Time

Your pace

9:02/mile

Distance

3.10 mi

Time

28:00

Pace

9:02/mile

Predicted race times at this pace (Riegel formula)

Race	Predicted time
5K	28:04
10K	58:31
Half Marathon	2:09:06
Marathon	4:29:11

For many runners, this comfortable speed sits right in the aerobic zone where conversation flows easily and the body efficiently builds endurance. Spending most of your weekly mileage here helps strengthen your heart and muscles without requiring heavy recovery time afterward. Focusing on a smooth, rhythmic stride at this pace makes it much easier to stay relaxed over longer stretches.

AI-generated insight

How to use the running pace calculator

1
Choose Find pace, Find time, or Find distance, depending on which value you already know.
2
Enter the two values you know — distance, time, and/or pace — in miles or kilometers.
3
Your result updates instantly, along with predicted times at 5K, 10K, half marathon, and marathon distances at that same pace.

How pace, time, and distance relate

Distance, time, and pace are three related values — knowing any two always determines the third.

Pace = time ÷ distance. Time = pace × distance. Distance = time ÷ pace. All three describe the same run from a different angle, so any two of them fully determine the third.

Worked example: a 5K (3.1 miles) finished in 28:00 gives a pace of 9:02 per mile (1,680 seconds ÷ 3.1 miles ≈ 541.9 seconds per mile). Flip it around: at a 9:02/mile pace, a 10-mile run would take about 1 hour 30 minutes.

How race time predictions work

The predicted times use Riegel's formula, published by exercise physiologist Peter Riegel in 1977 and still the standard method used by most race-time predictors and coaching tools:

T2 = T1 × (D2 / D1)^1.06

Worked example: a 28:00 5K predicts roughly a 58:31 10K, a 2:09:06 half marathon, and a 4:29:11 marathon — notice the exponent (1.06, not 1.0) means the predicted pace slows slightly at each longer distance, reflecting the real-world difficulty of sustaining the same intensity over more miles.

These are estimates based on one data point and a general formula — actual race results depend heavily on distance-specific training, pacing strategy, terrain, and conditions on race day.

Common race paces

Pace per mile	5K	10K	Half marathon	Marathon
7:00/mi	~23:17	~48:32	~1:47:05	~3:43:16
9:00/mi	~29:56	~1:02:24	~2:17:41	~4:47:04
11:00/mi	~36:35	~1:16:16	~2:48:17	~5:50:51

These are rounded reference points, each predicted from a one-mile time at that pace using the same Riegel formula the calculator uses — enter your own actual distance and time above for a more accurate, run-specific prediction at every race distance.

Training around a calorie or macro target for race season? Our Calorie Calculator (TDEE & BMR) → finds your daily calorie needs based on activity level.

Frequently asked questions

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