A single sneeze can propel respiratory droplets at very high speeds—commonly cited figures put peak sneeze velocities at around 160 km/h—and expel tens of thousands of droplets, which is one reason sneezes efficiently spread respiratory infections.
Speed and distance
High‑speed imaging and fluid‑dynamics studies show that sneezes produce a fast turbulent jet that carries droplets far beyond a few metres; peak speeds reported in popular summaries reach the order of 100 miles per hour (about 160 km/h), and the turbulent cloud can transport small droplets and aerosols several metres from the source.
Droplet numbers and size
A sneeze generates a wide range of droplet sizes from large ballistic droplets to tiny aerosols; popular estimates suggest a single violent sneeze can release tens of thousands to around 100,000 droplet particles, with many small droplets able to remain suspended and travel with air currents.
Why it matters
Because sneezes combine high speed, a large number of droplets and a turbulent carrier cloud, they raise the risk of transmitting pathogens to nearby people and contaminating surfaces; this is why respiratory hygiene (covering mouth and nose, distancing, ventilation) is recommended to reduce spread of infectious agents.
Takeaway
In short, sneezes can be extremely forceful and productive of droplets, capable of moving quickly and widely through the air—characteristics that help explain their role in rapid transmission of respiratory illnesses.