There’s no way to know where and how much visceral fat is hidden in your body without expensive imaging test. You’re unlikely to ever need those.

Waist size. This is an easy way to get a rough estimate. Wrap a tape measure around your waist over your belly button. (Don’t suck in your stomach!) In women, 35 inches or more is a sign of visceral fat. In men, it’s 40 inches. Warning: This is a crude tool, especially if you’re a very big person. And if you’re of Asian descent, the benchmark for visceral fat drops to 31.5 inches for women and 35.5 inches for men.
BMI. Body mass index is a formula for how much you weigh relative to your height. Online calculators can do the math for you. A BMI of 30 or higher is overweight. That could be a sign of visceral fat. If you’re Asian American, a BMI of 23 or higher could be a concern.