Pace Calculator

Distance

Enter numeric distance, e.g., 5, 10, 13.1

Unit

Time (HH:MM:SS)

All fields optional, but total time must be > 0.

Prefill via File (local-only)

JSON keys: {"distance":10,"unit":"km","time":"00:50:00"}. Nothing is uploaded.

Drag & drop a .json or .txt here to prefill. (Local only)

Pace Calculator – Quick Cheat Sheet

Pace = time per unit distance. Example: 5K in 25:00 → 5:00/km.
Speed = distance per time. Example above ≈ 12.0 km/h (≈ 7.46 mph).
Conversions: 1 mile = 1.609344 km, 1 km = 0.621371 mi.
Formulas:
Pace (/km) = total_seconds / kilometers
Pace (/mi) = total_seconds / miles
Speed (km/h) = kilometers / (seconds / 3600)
Speed (mph) = miles / (seconds / 3600)
Projections assume constant average pace (no fade/improvement).
Input tips: distance > 0 and time > 0 are required to compute results.
File/drag-drop accepts local .json or .txt (not uploaded) to prefill.

Edge cases & notes

For very slow paces, the format expands to H:MM:SS.
When unit is meters, the distance is converted to kilometers and miles internally.
Speeds/pace rounded for readability; underlying math uses full precision.