ZovaTool

Finish Time Calculator

Mode

Unit

What have you done so far?

Projection

Current pace
5:00 /km
Remaining distance
11.10 km
Remaining time
0:55:29
Finish total time
1:45:29
Finish clock time
5:50:33 AM
Pace used (remaining) /km
5:00
Avg speed
12.00 kph

How to use the Finish Time Calculator

  1. Pick a mode: Project Finish (you're already running and want to know when you'll finish) or Race Predictor (Riegel — predict a longer race from a known shorter time).
  2. Project Finish: enter distance covered so far, elapsed time and total race distance. Optionally override the pace for the remaining distance.
  3. Race Predictor: enter a known distance + time (e.g. 5K in 25:00) and a target distance — get the predicted time using T₂ = T₁ × (D₂/D₁)^1.06.
  4. Tweak the Riegel exponent (1.04 elite, 1.06 typical, 1.08 beginner) to match your endurance profile.
  5. Read finish total time, finish clock time and a table of predicted times for all common race distances.
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Race-day prediction in two formulas

The Riegel formula (T₂ = T₁ × (D₂/D₁)^1.06) is the gold standard for predicting race times across distances — it accounts for the fact that pace slows as distance grows because of accumulated fatigue.

The exponent 1.06 fits most road runners well, but elites can hold pace closer to 1.04 while newer runners often fade closer to 1.08. Calibrate the exponent against your own 5K → half marathon ratio if you have data.

Live projection is simpler: assume you finish at your current average pace, or override with a target pace for the remaining distance. Combine with a GPS watch to get a real-time finish clock prediction at every mile.