How to calculate fetal weight? With the development of science, technology and medicine, we can now calculate fetal weight in a variety of ways. The following are some common methods: 1. Ultrasonic inspection Ultrasonic inspection is the most commonly used method in recent years. It is painless, non-invasive and provides very precise data. The examination can be performed at any time during pregnancy, but for fetuses born after 36 weeks, ultrasound can also