10K Time Calculator

Use this calculator to estimate your 10-kilometer (10K) race time from a known training effort. Enter your current pace (minutes per kilometer) and the distance of your training run to get an evidence-based prediction for a 10K performance.

How it works

This tool uses a commonly-used endurance prediction approach (a variation of the Riegel formula) to extrapolate race time from a training performance. The calculator first computes your training time (pace × distance) and then predicts the 10K time using:

Where:

• T1 = your training time in minutes (pace × training distance)
• D1 = training distance (km)
• D2 = target distance (10 km)

Example

Suppose you ran 6 km at a 4:50 per km pace (4.833 minutes/km). Your training time T1 = 4.833 × 6 = 28.998 minutes. Predict for 10 km:

The predicted 10K time would be about 51 minutes and 52 seconds, with an average pace of about 5:11 per km.

Training tips

• Use a training effort (time trial or steady long run) that represents your current fitness.
• Longer training distances tend to give more reliable predictions for longer races.
• Consider conditions: terrain, weather, and fatigue can all affect race-day performance beyond what a single training run predicts.

Frequently Asked Questions

Is this prediction exact?

No. This prediction provides an evidence-based estimate based on pace and distance. Actual race performance depends on training specificity, nutrition, tapering, course profile, weather, and other factors.

What if my training distance is much shorter than 10K?

Predictions from short training efforts (e.g. 1–3 km) are less reliable. Longer, sustained efforts closer to race distance usually provide better estimates.

Can I use pace in min/mile?

This calculator expects pace in minutes per kilometer. Convert minutes per mile to minutes per kilometer before using. (1 mile ≈ 1.60934 km)

Want to save your results?

Use the PDF download button on the calculator to save your inputs and predicted results for later review or coaching notes.