Running Pace Calculator — With Splits

Give it any two of pace, finish time and distance and the third appears immediately. It also converts that pace into a treadmill speed, prints a cumulative split table for every kilometre or mile, and predicts your times at other race distances using Riegel's formula.

How to use

  1. Choose what you want to solve for: finish time, pace or distance.
  2. Pick kilometres or miles.
  3. Tap a race-distance button or type your own distance.
  4. Fill in the remaining value and the results and splits appear instantly.

The split table assumes an even pace throughout. In practice, starting the first kilometre 5–10 seconds slower than target usually costs you less than fading in the closing stages.

FAQ

How do I use the treadmill speed?

Type the treadmill number straight into the machine's speed control — 5:00/km is 12.0 km/h, for example. Most treadmills step in 0.1 increments, which is why it is rounded to one decimal.

How reliable are the predicted times?

They use Riegel's formula with an exponent of 1.06. Predictions between nearby distances (5K to 10K) hold up well, but a marathon predicted from a 5K is usually optimistic — long races depend far more on endurance training volume.

What is the difference between pace and speed?

They are the same thing inverted. Pace is minutes per kilometre; speed is kilometres per hour. Outdoor runners usually talk in pace, treadmills in speed.

Does switching to miles change my distance?

No. Switching units converts the same distance into that unit — 10 km becomes 6.21 miles and every result stays the same.

Related tools

  • BMI & BMR Calculator — Body mass index, basal metabolic rate, and daily calorie needs.
  • 1RM Calculator — Estimate your one-rep max and a per-set weight table from a lift.
  • TDEE Calculator — Find the calories you burn daily (TDEE) and your BMR, plus target calories and macros for any goal.
  • Running Interval Calculator — Turn a goal race time into training paces and lay out the session as per-rep targets with a total time.