Pace
{{ paceReadable }}
Speed
{{ speedReadable }}
h
m
s
m
s
MetricValue
Total time{{ timeReadable }}
Pace{{ paceReadable }}
Speed{{ speedReadable }}
SplitCumulative Time
{{ s.unit }} {{ s.time }}
Categories: Calculator , Converter , Health & Fitness
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Pace expresses the time needed to cover a unit of distance, while speed states how far you travel within one hour. Together they expose running efficiency, benchmark workouts, and illuminate training load. Because pace is unit-dependent, switching between kilometres and miles requires exact conversion so progress tracking remains consistent across terrains and sessions.

This calculator accepts any two of distance, elapsed time, pace, or speed. A lightweight reactive engine instantly resolves the missing values, synchronises kilometre–mile units, and builds split tables without contacting a server, giving friction-free feedback on track, road, or treadmill.

Enter 10 km and 00:50:00 to verify a 5:00 min/km rhythm, then review kilometre splits before race day. Wind, heat, and elevation can lengthen real-world times beyond these neutral-condition estimates.

Technical Details:

Concept Overview

Running pace (tp) divides elapsed time by distance, whereas speed (v) multiplies distance by 3600 then divides by time. Converting between the metrics, or between kilometres and miles, relies on the international factor 1.609344. Tracking both indicators supports tempo, interval, and endurance workouts by aligning effort boundaries with physiological adaptation windows.

Core Equation

tp= TD   ;   v= D T/3600
  • T – elapsed time in seconds
  • D – distance in kilometres
  • tp – pace in s/km (converted to min/km or min/mi for display)
  • v – speed in km/h or mph

Interpretation Bands

Pace Band (min/km)Example 10 km TimeIntensity Zone
> 6:3001:05:00Easy recovery
5:30 – 6:3000:55:00Endurance
4:45 – 5:3000:50:00Steady
4:00 – 4:4500:45:00Tempo
< 4:0000:40:00Interval/VO2 max

Faster bands incur higher cardiovascular load and should be used sparingly within structured workouts.

Worked Example

10 km in 00:50:00:

3000∕10=300 300 sec=5:00 10∕30003600=12

Result: 5 min/km pace and 12 km/h speed.

Assumptions & Limitations

  • Constant velocity throughout the distance.
  • Exact course measurement; GPS drift ignored.
  • Neglects wind resistance and gradient.
  • Pace conversion uses fixed kilometre–mile factor.

Edge Cases & Error Sources

  • Distance = 0 prevents division operations.
  • Time = 0 yields infinite speed.
  • Extreme paces (< 2 min/km) may exceed human capability.
  • Rounding seconds can distort long-distance splits.

Scientific Validity & References

Distance-time relations follow the velocity definition in classical mechanics. Training zones echo Daniels J. (Running Formula, 4th ed.) and IAAF endurance guidelines.

Privacy & Compliance: All computations run locally, processing only non-identifiable performance variables.

Step-by-Step Guide:

Follow these steps to generate pace, speed, and split tables.

  1. Select km or mi from the distance unit menu.
  2. Enter a numeric distance value.
  3. Fill in hours, minutes, and seconds or use the Advanced panel to set a target pace or speed, then press Apply.
  4. Review the highlighted pace and speed summaries.
  5. Switch to the Splits tab to inspect cumulative times for each kilometre or mile.

FAQ:

What inputs are required?

Provide any two of distance, time, pace, or speed; the calculator resolves the others automatically.

Can I mix km and mph?

Yes. Changing the speed unit automatically converts all related values and keeps calculations consistent.

Is my data stored?

No. All numbers stay in your browser and vanish when you refresh or close the page.

How precise are the splits?

Splits use whole-unit increments and round seconds; slight deviations may appear over very long distances.

Does this replace a GPS watch?

It complements wearables by planning target rhythms ahead of workouts but cannot capture live movement data.

Glossary:

Pace
Time taken per kilometre or mile.
Speed
Distance covered in one hour.
Split
Intermediate cumulative time marker.
Intensity Zone
Effort band linked to training effect.
Mile Factor
Constant 1.609344 for km-mile conversion.