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Pace Calculator

Health

Time (hh : mm : ss)

Common Race Paces

5K sub-20

4:00/km

15 km/h

10K sub-45

4:30/km

13.3 km/h

HM sub-1:45

4:59/km

12.0 km/h

Marathon sub-4h

5:41/km

10.5 km/h

About This Tool

🏃 Pace Calculator – Plan Your Run, Race, or Workout

Whether you are a beginner training for your first 5K or an experienced marathoner planning a negative-split race, the Pace Calculator solves for pace, finish time, distance, or speed from any two known values. Enter what you know and the tool computes everything else — including a full split table for your race checkpoint schedule.

Understanding Pace vs. Speed

Pace is the time required to cover one unit of distance, expressed as mm:ss per km or mm:ss per mile. A pace of 5:00/km means it takes exactly five minutes to run one kilometer. Speed is the inverse — distance divided by time, expressed in km/h or mph. A pace of 5:00/km is equivalent to exactly 12 km/h.

The relationship between pace and speed is: speed (km/h) = 60 / pace (min/km). Runners commonly use pace; cyclists and treadmills typically display speed. This calculator shows both so you can compare workouts across activities.

The Four Calculation Modes

1. Pace from Time and Distance

The most common use case: you finished a run and want to know your average pace. Enter the distance (e.g., 10 km) and your total time (e.g., 0:48:30). The formula is:

pace = total time ÷ distance

For 10 km in 48:30, the pace is 4:51 per km (12.37 km/h). The tool also shows the equivalent pace per mile (7:48/mi).

2. Finish Time from Pace and Distance

Planning a race? Enter your target pace and race distance to predict your finish time. For a half marathon (21.097 km) at 5:20/km, the estimated finish is 1:52:31. Use the optional split table to generate 1 km or 5 km checkpoints so you know exactly where you should be at each stage.

3. Distance from Pace and Time

Doing a timed workout? Set your pace and available time to find out how far you will travel. At 6:00/km for 45 minutes, you cover exactly 7.5 km. This mode is ideal for time-limited training runs and virtual challenges with a fixed duration.

4. Speed-to-Pace Conversion

Treadmills display speed in km/h or mph. Enter your treadmill setting (e.g.,10 km/h) to instantly convert it to a pace (6:00/kmor 9:39/mi). This mode also supports m/s for track coaches and swimming analysts.

Split Tables and Race Planning

Enable the Split Table toggle when solving for pace or finish time to generate a full checkpoint schedule. Choose a split distance (1 km, 5 km, 1 mile, or any custom interval) and the table shows:

  • The time needed to complete each individual split
  • The cumulative elapsed time at each checkpoint
  • Both split and cumulative distances for easy course verification

For a marathon at 5:00/km with 5 km splits, checkpoint 1 (5 km) is at 0:25:00, the halfway mark at 1:45:29, and the finish at 3:30:58.

Supported Units and Activities

The calculator supports meters, kilometers, miles, yards, feet, 400m lap, half marathon, and full marathon presets for distance. Speed can be entered in km/h, mph, or m/s. Pace units include per km, per mile, per 400m, per 500m, and per 100m — covering running, cycling, rowing, and swimming intervals.

All internal calculations normalize to seconds and meters before converting to display units, ensuring accuracy regardless of the unit combination you choose.

Tips for Accurate Pacing

  • Even splits: Running each kilometer at the same pace is the most efficient strategy for distance events. The split table helps you target consistent checkpoints.
  • Negative splits: Starting slightly slower and finishing faster is associated with better performance and reduced late-race fatigue in most endurance events.
  • Treadmill vs. outdoor: Treadmill pace does not account for wind resistance. Add approximately 0:10–0:15/km to a treadmill pace to estimate equivalent outdoor effort.
  • Elevation: Uphill running increases effort per km; your average pace will naturally slow. Use perceived effort rather than pace alone on hilly routes.

Example: Marathon Race Plan

Goal: finish a marathon in 3:30.

  • Target pace: 3:30:00 ÷ 42.195 km = 4:58/km (12.1 km/h)
  • 5 km checkpoint: 0:24:50
  • Halfway (21.1 km): 1:44:56
  • 30 km: 2:29:00
  • Finish: 3:29:41

Use this calculator to build exactly this plan — then export or copy the results to carry on race day.

Frequently Asked Questions

Is the Pace Calculator free?

Yes, Pace Calculator is totally free :)

Can I use the Pace Calculator offline?

Yes, you can install the webapp as PWA.

Is it safe to use Pace Calculator?

Yes, any data related to Pace Calculator only stored in your browser (if storage required). You can simply clear browser cache to clear all the stored data. We do not store any data on server.

How does the Pace Calculator work?

Select a calculation mode — solve for pace, finish time, distance, or speed — then enter the two known values. The calculator normalizes all inputs to seconds and meters internally, applies the core formula, and displays the result in your chosen units.

What is the difference between pace and speed?

Pace is the time needed to cover one unit of distance (e.g., 5:00 per km), while speed is the distance covered per unit of time (e.g., 12 km/h). They are inversely related: a faster pace means a higher speed. Both metrics are displayed side by side in the results.

How are split times calculated?

The split table divides your total distance into equal intervals of your chosen split distance, then multiplies each interval by your pace. Cumulative times count up from the start, showing you exactly when you should reach each checkpoint.

Which distance units and sports does this calculator support?

Supported distance units include meters, kilometers, miles, yards, feet, 400m lap, half marathon, and marathon. The pace and speed results apply to any timed endurance activity including running, walking, cycling, rowing, and swimming.

Why might my actual race time differ from the calculated time?

The calculator assumes a constant, average pace for the entire distance. In practice, terrain changes, fatigue, aid station stops, wind, and pacing strategy all affect real performance. Use the result as a planning target, not a guaranteed outcome.

Can I use this for a marathon or half marathon?

Yes. Select the marathon or half marathon preset from the distance unit dropdown, enter your target pace or goal time, and the tool computes the missing value. The optional split table breaks the race into 5 km or 1 mile checkpoints for a full pacing plan.