Kilometres and Miles
Use the exact mile conversion and keep distance markers separate from pace-unit labels.
The distance conversion used here
PaceRibbon uses exactly 1 mile = 1.609344 kilometres, or 1,609.344 metres. Distances are stored in millimetres, making one mile exactly 1,609,344 internal units. A convenient approximation such as 1.6 km is not used in the calculation.
| Distance | Kilometres | Metres |
|---|---|---|
| 1 mile | 1.609344 | 1,609.344 |
| 5 miles | 8.04672 | 8,046.72 |
| 10 miles | 16.09344 | 16,093.44 |
| 1 kilometre | 1 | 1,000 |
A pace conversion keeps the plan unchanged
For an 8:00 mile, the per-kilometre pace is about 4:58 after rounding. Changing the displayed unit should keep the same distance and duration. It should not replace a mile with a kilometre while leaving the numeric distance untouched.
A marker conversion is a location change
The 5 km marker and the 5 mile marker are different points. In a four-hour marathon, the 5 km row is about 0:28:26 and the 5 mile row is about 0:45:46. A side-by-side table can show both sequences, but equal row numbers do not make their physical locations equal.
Keep one source plan
- Choose the exact race distance and finish-time target first.
- Create the kilometre and mile markers from that same plan.
- Retain km or mi beside every distance on a mixed-unit sheet.
- Include one halfway marker and one finish marker.
For a distance entered as a decimal, PaceRibbon rounds the converted value to the nearest millimetre for its internal distance. The named mile, half-marathon and marathon presets use their fixed exact constants.