Varroa Mite Count Calculator

A standard varroa wash uses about 300 bees, which is roughly a half cup of bees. The tool works with any sample size, but 300 bees is the common reference that the 3 percent threshold is built around.

It is the mite count scaled to a sample of 100 bees. Because it is per 100 bees, the same number is also the infestation percent. For example, 9 mites in 300 bees is 3 mites per 100 bees, or a 3 percent infestation.

Many beekeeping programs use about 3 mites per 100 bees, a 3 percent infestation, as an economic threshold where mite damage starts to outweigh the cost of treating. Below it, colonies usually cope; above it, action is often advised.

Both estimate the same mites per 100 bees. An alcohol wash kills the sample but is very consistent, while a sugar roll keeps bees alive but can miss a few mites. Use the method your local guidance prefers.

No. It is a general guideline. The right action level changes with the season, your local mite pressure and your management goals, so check current advice from a beekeeping association or extension office.