If you've ever graded a tapered jogger from M to 2XL and noticed the taper completely disappears in the larger sizes — you're not alone. It's the #1 grading mistake in athleisure.

Here's what's happening:

Most pattern makers apply uniform grade increments from hip to hem across all sizes. This works fine for straight-leg pants. But on a tapered jogger, the magic is in the knee-to-hem ratio — and flat grading destroys it.

The quick math:

Your base size M might have a knee width of 9" and a hem of 7" — a taper ratio of 22%.

If you grade both the knee AND the hem by the same ½" per size, by the time you hit 2XL, your knee is 11" and your hem is 9". Your taper ratio dropped to 18%. At 4XL? You're at 15%. That's not a jogger anymore — that's a relaxed-fit chino.

The fix:

Grade the hem at only 40–60% of your knee increment. So if the knee goes up ½" per size, the hem only goes up ¼"–⅜".

This maintains the taper silhouette all the way up to 5XL.

There's more to it — inseam vs. outseam distribution, size-break strategies above XL, fabric stretch compensation — but this ratio rule alone will transform your extended size grading.

I teach the complete system in my pro certification course. If you're grading athleisure patterns professionally, this is the skill that separates production-ready work from amateur attempts.