Utilities / Pace Calculator
OneFreePlace · Tool #132

Turn a race goal into a pace plan you can actually follow.

Solve for pace, finish time or distance; then build exact kilometre, mile, track-lap or custom checkpoints. Choose even, negative or positive pacing while keeping the final clock exact, compare small pace changes, and estimate equivalent race performances with a transparent model.

✓ Time · pace · distance✓ Exact split table✓ Negative / positive splits✓ 400 m / 800 m checkpoints✓ Race estimates
Pace Calculator
Goal solving · exact splits · pace band · race equivalents
Goal builder

Start from the numbers you already know.

Race distanceHalf 21.0975 km · marathon 42.195 km.
Finish timeHours, minutes, seconds.
Split planStrategy redistributes pace while preserving finish time.
A 6% negative plan begins slower and finishes faster. The whole curve is rescaled so the final cumulative time stays exactly on target.
Calculated pace
Calculating
—
average pace per kilometre
Enter a valid target.
Finish time——
Pace / mile—average moving pace
Pace / km—average moving pace
Average speed——
400 m equivalent—at average pace
800 m equivalent—at average pace
——

Split table

The final partial checkpoint is always included, so cumulative time ends exactly on the target—not one marker short.

CheckpointSegmentSegment paceSplit timeElapsed

Pace-change sensitivity

See what ±5 or ±10 seconds per kilometre does to the finish clock over this exact distance.

Equivalent race estimates

Uses Riegel: T₂ = T₁ × (D₂/D₁)^e. The default exponent 1.06 is editable.

i
Equivalent race times are estimates, not promises.The split table is deterministic arithmetic. Race-equivalent estimates assume broadly comparable fitness, preparation and course conditions.