Fraso / nomograms

Running

Running pace

Distance and pace against finishing time.

A running pace nomogram: three vertical scales, D (1 to 50) on the left, T (3 to 400) in the middle and p (3 to 8) on the right. A straight line laid across any two scales cuts the third at the value that satisfies T = D · p.5040302520161310865432.521.61.31Dkm87.676.76.465.75.454.74.54.343.83.63.43.23pmin/km400300200160100806450403020161086.4543Tmin

Readings

km
min/km
min

Drag the red line, or type into any two boxes — the third is solved. The marked box is the one being solved for.

Print at 100% scale, then check the 100 mm bar with a rule before trusting a reading.

Why this one is an instrument

Race planning is a question about sensitivity: how much time does five seconds a kilometre actually cost over the distance, and is that a price worth paying in the first half. The pace scale is narrow and the time scale is wide, so the leverage of small pace changes over long distances is visible as a geometric fact rather than something you have to work out.

Equation
T = D · p
Constants
T in minutes
Ranges
D 1–50 km · p 3–8 min/km
Reading
Any two values fix the third. Outside the printed ranges the instrument stops being valid — that is what the end marks are for.

These are drawn from the stated equation and nothing else. Where an equation is itself an approximation — hyperfocal distance and tap drill sizes both are — the instrument inherits that approximation exactly, no better and no worse.