To calculate the sagitta of a mirror, enter its diameter and focal length and click "Calculate sagitta". To calculate the focal length of a mirror, enter its diameter and sagitta and click "Calculate focal length".
This calculator knows no units. Make sure you are entering all of your parameters in the same units or nonsensical results will be produced.
| Mirror diameter (required) | |
| Mirror sagitta | |
| Mirror focal length |