Recorded efforts
Distances in meters. Time accepts seconds, m:ss or h:mm:ss; seconds after a colon must be below 60.
Two-point speed
Fit a distance–time line from two recent all-out efforts. Both recorded times are needed.
Examples use 1200m + 3200m:
One recent 5K
CV velocity = 5K velocity × 0.9533. Pace = 5K pace ÷ 0.9533, so the convention is slightly slower than the entered 5K pace.
Tinman convention
A separate single-race training shortcut; it does not fit CS or D′.
Read the fit
CS = (D₂ − D₁) ÷ (T₂ − T₁); D′ = D₁ − CS × T₁. Efforts are normalized by duration, so entering them in reverse order gives the same fit. Time prediction uses T = (D − D′) ÷ CS. Meter and second inputs are retained unrounded for calculation; displayed clocks round to whole seconds.
Use comparable, recent all-out efforts at different durations, approximately 2–30 minutes. Two points always define a line: this calculator cannot measure fit error, verify maximal effort, diagnose physiology or guarantee a future race time. Zero reserve is a mathematical boundary. The 2019 two- versus three-test study supports a specific field protocol, not every possible pair of performances.
The retained Tinman factor is a coaching convention rather than an individualized critical-speed test. The two estimates need not agree; they should not be treated as interchangeable measurements.