Private browser-based running planner

Running Pace & Race-Time Calculator

Calculate pace, finish time, or distance; convert kilometre and mile units; and build a complete race split plan.

Pace, time & distanceKilometres & milesRace presetsCustom split plansRace predictions100% client-side

What do you want to calculate?

Distance

Enter a custom distance or choose a race preset.

Elapsed time

Pacing plan

0% produces even splits. Keep changes modest.

Shows the estimated finish clock time.

Running result

Finish time

50:00

Calculated elapsed time

Distance

10 km

6.214 miles

Pace per kilometre

5:00 /km

Average pace

Pace per mile

8:03 /mi

Average pace

Speed

12.00 km/h

7.46 mph

Finish clock

7:20 AM

Starting at 06:30

Equivalent race times

Riegel model estimate; marathon predictions from shorter runs may be optimistic.

Default: 1.06

Model

T₂ = T₁ × (D₂ / D₁)e

RaceTime
1K04:21
1 Mile07:13
5K23:59
10K50:00
Half Marathon01:50:19
Marathon03:50:01

Kilometre split plan

Negative strategy · 2% variation · exact total time preserved.

4:525:005:08Split 1Split 10
SplitDistancePace /kmSplit timeCumulative
1 km1 km5:0605:0605:06
2 km1 km5:0505:0510:11
3 km1 km5:0305:0315:14
4 km1 km5:0205:0220:16
5 km1 km5:0105:0125:17
6 km1 km4:5904:5930:16
7 km1 km4:5804:5835:14
8 km1 km4:5704:5740:11
9 km1 km4:5504:5545:06
10 km1 km4:5404:5450:00

Planning estimate, not a performance guarantee

Terrain, elevation, weather, fatigue, fuelling, measurement accuracy, and training can change real-world pace. Use the plan as a guide and adjust safely to current conditions.

Running Pace, Time, and Distance Formulas

Running pace describes how long it takes to cover one kilometre or mile. Choose the value you want to find, then provide the other two. The calculator normalizes kilometres, miles, hours, minutes, and seconds before calculating every result.

Pace

Time ÷ distance

Finish time

Distance × pace

Distance

Time ÷ pace

Build a Practical Pacing Plan

A target average pace does not require every split to be identical. Use an even plan for consistent pacing, a negative split to progress from controlled to faster running, or a positive split to model a faster start. The planner normalizes every segment so the final cumulative time always equals the target.

  • Switch between kilometre and mile splits
  • Include the exact final partial split
  • Compare segment pace and cumulative time
  • Add an optional start time for finish-clock planning
  • Export the complete pacing table as CSV
  • Keep the variation modest for a realistic plan

Understanding Equivalent Race Times

Equivalent times use the Riegel endurance model, written as T₂ = T₁ × (D₂ ÷ D₁)exponent. The adjustable exponent represents how pace may change with distance. The common 1.06 default is a useful starting point, but training specificity, fatigue resistance, terrain, weather, fuelling, and race execution can produce a different result.

A study of recreational endurance runners found Riegel predictions reasonably calibrated through the half marathon but often too optimistic for the marathon. Treat predictions from a much shorter performance as a comparison, not a target you must achieve.

Training Estimate Note

This calculator is for planning and education, not medical or coaching advice. Race predictions assume comparable effort and conditions. Adjust targets for course elevation, weather, fitness, recovery, health, and experience, and avoid using a calculated pace to override pain or warning symptoms.

Running Pace & Race-Time Calculator FAQs