To put it in mathematical notation
vmax = max(viewportWidth, viewportHeight) * 0.01;
vmin = min(viewportWidth, viewportHeight) * 0.01;
So, the max of 1280px and 720px is 1280px, so in that case 1vmax = 0.01 * 1280 = 12.8px
Once you know that it becomes easy
Nvmax = N * 12.8px
So for example 3vmax = 3 * 12.8 = 38.4, 0.25vmax = 0.25 * 12.8 = 3.2px, etc
I’m still not sure why you want to know, as the whole point of vmin and vmax is to do relative sizing with respect to the viewport, why do you care what that becomes in absolute numbers?