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CARDIO · PACE

Running Pace Calculator

Calculate pace per kilometer and mile and project race finish times from your current run.

Try a preset

Distance (km)
Time (min)

Result

PACE / KM
5:00/km
PACE / MILE
8:03/mi
5K PROJECTION
25:00
10K PROJECTION
50:00
MARATHON
210:58

Projected Race Times

At the current pace, longer race targets stack as a clean duration ladder.

5K
5 km
25:00
10K
10 km
50:00
Half Marathon
21.1 km
105:29
Marathon
42.2 km
210:58
00:00210:58

How to use it

  1. Enter your target distance and goal time to find required pace, or enter distance and pace to project finish time. Use race-pace calculation for goal-setting and training-pace calculation for daily workouts — these are different numbers.
  2. Easy and long run pace should be 60–90 seconds per mile slower than your current 5K race pace. Running all workouts at race pace is the most common cause of overtraining and injury in recreational runners.
  3. Apply the 80/20 principle: 80% of weekly mileage at easy conversational pace, 20% at moderate-to-hard effort. This builds aerobic capacity while managing recovery cost.
  4. Translate 5K pace to other race distances with these rough multipliers: 10K ≈ 5K time × 2.09, Half Marathon ≈ 5K time × 4.67, Marathon ≈ 5K time × 10.0.
  5. Adjust for conditions: each degree above 60°F adds approximately 1% to finish time. Wind above 10 mph, significant elevation, and rain all extend pace. Recalculate realistic targets for race-day conditions.
Questions people usually ask
Which formula is used here?

Converts a known distance and time into pace metrics, then projects race times using constant pace assumptions.

Can I use metric or imperial units?

Yes. This tool supports both metric and imperial units and remembers your preference.

Is this medical advice?

No. This tool provides general fitness estimates and should not replace medical guidance.

Is this tool free and private to use?

Yes. AI Fit Hub tools are free, no-signup browser tools. Inputs stay in your browser unless you choose to share a URL.

Do these tools replace medical guidance?

No. These outputs are general fitness estimates — not medical advice.

Can I switch between metric and imperial units?

Yes. Every tool supports both systems and remembers your preference in localStorage.

Related Resources

Learn the decision before you act

Every link here is tied directly to Running Pace Calculator. Use the explanation, formula, examples, and benchmarks to pressure-test the calculator output from first principles.

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General fitness estimates — not medical advice. Consult a healthcare professional for medical decisions.