What size are typical blood droplets in low-velocity impact spatter?

Typical blood droplets in low-velocity impact spatter tend to be larger due to the nature of the forces involved in their creation. Low-velocity impacts are usually classified as those that occur from activities such as blunt force trauma or the dropping of blood from a height of less than a few feet. The droplets that result from these types of impacts generally measure about 3mm or more in diameter.

The larger size can be attributed to the relative lack of force during the impact, allowing larger droplets to form and fall instead of breaking into smaller droplets that would be characteristic of higher velocity impacts. The physics of blood droplets shows that droplet size correlates with the type of impact force applied—lower velocities allow for the coalescence of larger amounts of blood without as much dispersion or fragmentation, unlike in high-velocity spatter, where the forces often create much smaller droplets.