Where the math comes from
One documented rule powers the whole tool.
The tracked Roblox description states it as the game's first mechanic line: "Every step = +1 Speed" (Rolimon's copy of the official description, checked 2026-10-03).
Subtract your current Speed from the target. The answer is the exact number of steps you still need, because each step pays exactly one Speed. The maximum-with-zero simply means a target at or below your current Speed costs nothing.
That is the entire calculation — there is no rate guessing, because the exchange rate is the one number the official description states outright. Everything else on this page explains how to use the result, not how to adjust it.