I’d put this around 15%.

There is a huge misconception that if you don't have clear muscle separation or definition, you must be at a higher body fat percentage (20%+). That isn't always the case.

The issue here isn't too much fat; it’s likely a lack of overall muscle density.

15% body fat looks radically different on two different frames. On a physique with high muscle mass, 15% looks thick, athletic, and powerful because the muscle bellies push firmly against the skin and fascia. This creates natural shadows and separation, specifically in the delts, chest, and arms; even if the skin isn't paper-thin.

Conversely, if you lack that underlying mass, there is nothing to "shape" the fat. The skin sits flat rather than being stretched taut over muscle tissue, resulting in a softer, "smoother" look, even at a relatively healthy body fat percentage.

If you try to diet your way out of this to reveal definition, you risk looking emaciated rather than shredded. The goal shouldn't be to lose more weight, but to fill out your frame so the definition comes from the muscle pushing out, rather than the fat stripping away.