What this result means
Choose what you want to calculate and enter the two values you know. Pace is elapsed time divided by distance; the tool also uses the exact international-mile relationship to show equivalent min/km, min/mile, km/h and mph results. [1][2]
Choose the result you need
Calculate pace when you know distance and elapsed time. Calculate elapsed time when you know distance and a constant target pace. Calculate distance when you know elapsed time and a constant pace.
Pace and speed describe the same movement differently
Pace is time per unit of distance, such as minutes per kilometre. Speed is distance per unit of time, such as kilometres per hour. A lower time-per-distance number corresponds to a higher speed, but neither number by itself rates effort or fitness. [2]
Running and walking use the same calculation
The relationship between distance, elapsed time and average pace does not change with activity label. That is why one calculator can serve a run, walk or other steady-distance activity without asking for age, sex, weight or fitness level.
Why min/km and min/mile are exact equivalents
An average does not show every part of an activity
A single average can hide faster and slower sections, stops, hills, surface changes, wind and fatigue. A calculated finish time or distance also assumes the entered pace remains constant for the whole period.
Why a watch or treadmill may show something different
GPS distance, treadmill calibration, auto-pause settings and device rounding can change the source values. This calculator uses exactly what you enter and cannot correct a measurement error in the original activity record.
What this result cannot tell you
The result cannot determine whether a pace is good, safe, sustainable or appropriate for your health or training. It does not diagnose a condition or replace individual exercise or medical guidance.
Formula and assumptions
- Version
- Pace, elapsed-time and distance relationship, pace-time-distance-v1
- Rounding
- LongevityMate display policy: use exact decimal and integer-ratio arithmetic, then round displayed pace and elapsed time once to the nearest second, half up, and distance and speed once to two decimals. A positive value below display resolution is shown with a less-than sign, not as zero.
- Worked example
- For 5 kilometres in 25 minutes: 1,500 seconds ÷ 5 = 300 seconds per kilometre, displayed as 5:00 min/km. Using the exact mile relationship, the same average is about 8:03 min/mi, 12.00 km/h and 7.46 mph. [1]
Who this is for — and when not to use it
Intended use
Neutral average-pace, elapsed-time and distance arithmetic for a measured or planned run or walk, using the user's own distance and time values.
Not intended for
This tool does not assess fitness, effort, safety, health, injury risk or performance; prescribe training; predict variable-effort race outcomes; or estimate calories, steps, stride length, VO2 max or training zones.
Exclusions
- Fitness, performance, health or safety classification
- Race prediction that assumes performance over a different distance
- Training-zone or exercise prescription
- Calories, METs, steps, stride length or body-based estimates
- Medical, symptom, injury or return-to-exercise decisions
- Activities where vertical gain, terrain or stops must be modelled separately
Evidence sources
- 1. NIST Guide to the SI, Appendix B: Conversion Factors — National Institute of Standards and Technology. Accessed Aug 17, 2026.
- 2. The International System of Units (SI), NIST Special Publication 330 — National Institute of Standards and Technology. Accessed Aug 17, 2026.