Pace Calculator

What Is a Pace Calculator?

Pace is the fundamental metric of running. It tells you how many minutes it takes to cover one kilometre or one mile, giving you a consistent way to measure effort across different distances and terrains. Whether you are training for your first 5K or aiming for a personal best in the marathon, understanding your pace helps you set realistic goals and execute a smart race strategy.

This calculator works in three directions. Enter your distance and time to find your pace. Enter your pace and distance to find your expected finish time. Or enter your pace and time to find how far you will run. It handles both metric (min/km) and imperial (min/mile) units and automatically projects finish times for standard race distances: 5K, 10K, half marathon (21.0975 km), and full marathon (42.195 km).

Pacing is especially critical in longer races where starting too fast leads to hitting the wall — a dramatic loss of energy in the final kilometres. Experienced runners use pace calculators to plan negative splits (running the second half faster than the first) and to set target times for each mile or kilometre marker. The projections in this calculator use a simple linear model; for more precise marathon predictions, factor in that pace typically slows 5-10% over the final third of the race.

How Do You Use This Pace Calculator?

Enter any two of the three values — distance, time, and pace — and the calculator will solve for the third. View projected finish times for popular race distances based on your current pace.

1. Enter the distance you ran or plan to run (in km or miles).
2. Enter the time taken or your target time (in hours, minutes, seconds).
3. Alternatively, enter your known pace (min/km or min/mile) instead of time.
4. Click Calculate to see pace, speed, and finish time projections.
5. Review projected finish times for 5K, 10K, half marathon, and marathon distances.
6. Adjust inputs to plan different race strategies or training targets.

How Does the Pace Calculator Formula Work?

The formula used: Pace = Time / Distance; Speed = Distance / Time; Finish Time = Target Distance × Pace

What Are Some Example Calculations?

A runner completes 5 km in 25 minutes: Pace = 25 / 5 = 5:00 min/km. Speed = 12 km/h. Projected half marathon (21.1 km) time = 1:45:30.

When Should You Use a Pace Calculator?

Use the pace calculator when setting goals for an upcoming race. A realistic target time based on your current training pace prevents the common mistake of going out too fast on race day. Enter your recent long run or time trial data to see projected finish times for longer distances, then adjust for conditions and experience.

The calculator is equally useful during training. Coaches prescribe workouts at specific paces — easy runs, tempo runs, and interval sessions all have target pace ranges. Enter your threshold pace and the prescribed distance to know exactly what split times to hit. For treadmill runners, use the speed output to set the correct belt speed in km/h or mph.

What Do These Terms Mean?

What Are the Best Tips to Know?

• For marathon predictions from a 10K time, multiply your 10K time by 4.65 for a more realistic estimate than simple linear scaling.
• Train most of your weekly mileage at an easy pace (60-90 seconds slower per km than your race pace).
• In hot weather, expect your pace to slow by 1-3% for every 5°C above 15°C.
• Use negative splits in races: run the first half slightly slower than your target pace and speed up in the second half.
• Record your pace data from training runs to track fitness improvements over weeks and months.

What Mistakes Should You Avoid?

• Confusing pace (minutes per km, lower is faster) with speed (km per hour, higher is faster).
• Assuming your 5K pace can be maintained for a marathon — expect to slow by 15-20% over the longer distance.
• Forgetting that elevation gain significantly slows pace: add roughly 30 seconds per km for every 100 metres of climbing.
• Setting a race target based on a single fast training run rather than a consistent average over multiple sessions.