Free Tool

Pace Calculator & Lactate Threshold

Convert pace and speed, estimate your lactate threshold, predict race times, and explore pace tables for every distance.

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Understanding Running Pace

Running pace tells you how many minutes it takes to run one kilometre (min/km). It is the most important metric for runners when planning training and racing.

Speed in km/h is the inverse of pace. A pace of 5'00"/km equals a speed of 12 km/h. Both are useful: pace for planning intervals and race strategy, speed for comparing against your lactate threshold.

Lactate Threshold: The Key to Training

Your lactate threshold is the speed at which your body produces lactate faster than it can clear it. It roughly corresponds to your 10K race pace and sits at about 85% of your VO2Max.

Your training paces are calculated relative to your lactate threshold:

Why Calculate with RunRight?

RunRight reads your running data from Apple Health — training history, heart rate, VO2Max — and creates an adaptive training plan that automatically updates your paces after every run.

No manual calculation needed: RunRight programmes your workouts directly to your Apple Watch with the right paces, based on your current fitness.

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Frequently Asked Questions

How do you calculate running pace?

Running pace is calculated by dividing your time by the distance. For example, if you run 10 km in 50 minutes, your pace is 5'00"/km. Our calculator instantly converts between pace (min/km) and speed (km/h).

What is lactate threshold and how do you calculate it?

Lactate threshold is the speed at which your body produces lactate faster than it can clear it. You can estimate it from a lab test, a field test, or from a recent race result. Your 10K race pace roughly corresponds to your lactate threshold speed.

What is the difference between lactate threshold and VO2Max?

VO2Max measures your maximum oxygen uptake in ml/kg/min. Lactate threshold is the speed at which lactate accumulates, expressed in km/h. Your lactate threshold typically sits at about 85% of VO2Max. Both metrics complement each other: VO2Max shows your potential, while lactate threshold reflects your current performance level.

What pace should I run a marathon at?

Marathon pace is typically 75-80% of your lactate threshold speed. For a runner with a lactate threshold of 15 km/h, that means roughly 11-12 km/h, or a pace of 5'00" to 5'27"/km. Use our pace table to find the right pace for your target time.

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