Optics
Lens Power
The power of a lens in diopters is the reciprocal of focal length in meters.
Variables
PD (diopters)
Power
fm
Focal length
Your notes
0/5000
Check value
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- f = 2 m (Focal length)
Result: P = 0.5 D (diopters)
Other optics formulas with the same quantities
- Lensmaker's Equation (Lenses) shares Focal length
- Mirror Equation (Reflection) shares Focal length
- Focal Length and Radius (Reflection) shares Focal length
- F-Number (f-stop) (Optical Instruments) shares Focal length
- Depth of Field (Optical Instruments) shares Focal length
- Spherical Mirror Focal Length (Reflection) shares Focal length
Where this formula is listed
- Optics formulas, under Lenses, alongside Lens Magnification.
- In the optics list it comes after Lens Magnification and before Combined Lens Power.
- Optics formula sheet, one of 34 formulas printed with symbol keys and SI units.
- The full formula index, grouped by category and topic.
Common questions
What is the Lens Power formula?
Lens Power is written P = 1/f. The power of a lens in diopters is the reciprocal of focal length in meters. It belongs to Optics, under Lenses.
What are the units in P = 1/f?
In SI units, P is power, measured in D (diopters); f is focal length, measured in m.