treadmillpace-mph-to-pace

Zero-dependency JavaScript library and CLI for treadmill speed ↔ running pace conversions.

Extracted from the conversion engine behind TreadmillPace.com — a free treadmill pace calculator and printable chart.

npm install treadmillpace-mph-to-pace

CLI

After install, run mph-to-pace (or use npx treadmillpace-mph-to-pace without installing):

# mph → min/mile + km/h + 5K time
mph-to-pace 6
# 6.0 mph  →  10:00/mi  (6:13/km)
# 9.7 km/h  ·  5K 31:04  ·  Run

mph-to-pace --kmh 10
# 6.2 mph  →  9:41/mi  (6:00/km)
# 10.0 km/h  ·  5K 30:00  ·  Run

mph-to-pace --pace 8:00
# 7.5 mph  →  8:00/mi  (4:58/km)
# 12.1 km/h  ·  5K 24:51  ·  Run

mph-to-pace --pace-km 5:00
# 7.5 mph  →  8:03/mi  (5:00/km)
# 12.0 km/h  ·  5K 25:00  ·  Run

mph-to-pace --incline 5 6
# 6 mph @ 5% incline ≈ 11:00/mi flat-equivalent pace

API

import {
  speedToPace,
  paceToSpeed,
  mphToKmh,
  kmhToMph,
  formatPace,
  parsePace,
  fromMph,
  fromKmh,
  fromPacePerMile,
  finishMinutes,
  inclineAdjustPace,
} from "treadmillpace-mph-to-pace";

speedToPace(6);           // 10  (minutes per mile)
paceToSpeed(8);           // 7.5 (mph)
formatPace(10);           // "10:00"
parsePace("8:30");        // 8.5

fromMph(6);
// {
//   mph: 6,
//   kmh: 9.656064,
//   pacePerMile: "10:00",
//   pacePerKm: "6:13",
//   fiveKMiles: "31:04",
//   fiveKKm: "31:04",
//   effort: "Run",
//   ...
// }

finishMinutes(6, 5 / 1.609344);  // 5K time in minutes at 6 mph
inclineAdjustPace(10, 5);        // 12 — flat-equivalent pace estimate

Works in Node.js 18+ and any modern browser (ES modules, no build step).

Formulas

All conversions assume matching units — keep miles with mph and kilometers with km/h.

| Conversion | Formula | |------------|---------| | Speed → pace | pace (min) = 60 ÷ speed | | Pace → speed | speed = 60 ÷ pace (min) | | mph → km/h | km/h = mph × 1.609344 | | km/h → mph | mph = km/h ÷ 1.609344 | | Race finish time | minutes = (distance ÷ speed) × 60 | | Incline estimate* | flat pace ≈ treadmill pace × (1 + grade% × 0.04) |

*Incline adjustment is an illustrative estimate for moderate running speeds, not a physiological model. See the incline calculator on the site.

Worked examples

6 mph → pace

pace = 60 ÷ 6 = 10:00 per mile
km/h = 6 × 1.609344 = 9.7 km/h
pace/km = 60 ÷ 9.656 = 6:13 per km
5K time = (3.107 mi ÷ 6 mph) × 60 = 31:04

8:00/mi → speed

mph = 60 ÷ 8 = 7.5
km/h = 7.5 × 1.609344 = 12.1

Related / Live Demo

This package powers the free tools at TreadmillPace.com:

• Live Demo — Calculator: https://treadmillpace.com/
• Live Demo — Printable Chart: https://treadmillpace.com/chart/

Also useful:

• 5K goal-time → belt speed
• Incline effort estimate
• km/h to min/km chart

Development

cd packages/mph-to-pace
npm test
node cli.js 6

License

MIT © TreadmillPace