Enter the diopter measurement into the calculator to determine the focal length in millimeters.
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Diopter To Mm Formula
The following formula is used to calculate the focal length in millimeters from a diopter measurement.
FL = 1000 / D
Variables:
- FL is the focal length in millimeters (mm)
- D is the diopter measurement (diopters)
To calculate the focal length in millimeters, take the reciprocal of the diopter measurement and multiply it by 1000. This converts the measurement from meters to millimeters. For example, a 2 diopter lens would have a focal length of 1/2 meter, or 500 millimeters.
| Diopters (D) | Focal length (mm) |
|---|---|
| 0.25 | 4000.000 |
| 0.50 | 2000.000 |
| 0.75 | 1333.333 |
| 1 | 1000.000 |
| 1.25 | 800.000 |
| 1.5 | 666.667 |
| 2 | 500.000 |
| 2.5 | 400.000 |
| 3 | 333.333 |
| 3.5 | 285.714 |
| 4 | 250.000 |
| 5 | 200.000 |
| 6 | 166.667 |
| 7 | 142.857 |
| 8 | 125.000 |
| 9 | 111.111 |
| 10 | 100.000 |
| 12 | 83.333 |
| 15 | 66.667 |
| 20 | 50.000 |
| *Formula: Focal length (mm) = 1000 / D. Example: 2 D → 500 mm. | |
What is a Diopter To Mm?
A diopter is a unit of measurement used in optics to determine the optical power of a lens or curved mirror. It is equal to the reciprocal of the focal length measured in meters. Therefore, if you want to convert diopters to millimeters, you would take the reciprocal of the diopter measurement and then convert that measurement from meters to millimeters. For example, a 2 diopter lens has a focal length of 1/2 meter, or 500 millimeters.
How to Calculate Diopter To Mm?
The following steps outline how to calculate the Diopter To Mm using the formula: FL = 1000 / D
- First, determine the diopter measurement (D).
- Next, use the formula FL = 1000 / D to calculate the focal length in millimeters (FL).
- Finally, calculate the Diopter To Mm.
- After inserting the value of D and calculating the result, check your answer with the calculator above.
Example Problem:
Use the following variables as an example problem to test your knowledge.
diopter measurement (D) = 2
