About the Mirror Equation Calculator
Curved mirror equation (1/f = 1/v + 1/u) with radius of curvature, image position and magnification.
Also known as: concave mirror calculator, convex mirror, spherical mirror formula.
How to use this calculator
- Enter mirror, radius of curvature, object distance.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
1/f = 1/v + 1/u, f = R/2
Worked example
Using the values pre-filled in the calculator above:
- Mirror: Concave (converging)
- Radius of curvature = 40 cm
- Object distance = 30 cm
the calculator returns:
- Image distance: 60 cm
- Focal length: 20 cm
- Magnification: -2 ×
- Image type: Real and inverted