What Is a Pie Wheel?

A pie wheel is one formula drawn as a circle: the top equals the bottom sections multiplied together.

Flow RateTap a section to cover the quantity you want to find.

Each section holds one named quantity with its units, such as Flow in ft³/s. A number goes in a section only if it is that quantity.

Above the lineThe result

The top equals the bottom sections multiplied together.

The lineDivide

The horizontal line works like a division bar.

Below the lineMultiply

Sections side by side are multiplied.

This wheel says: Flow = Area × Velocity.