Enter the object distance (in) and the focal length (in) into the Image Distance Calculator. The calculator will evaluate and display the Image Distance.

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## Image Distance Formula

The following formula is used to calculate the Image Distance.

1/Di = 1/F - 1/O

- Where Di is the Image Distance (in)
- F is the object distance (in)
- O is the focal length (in)

To calculate the image distance, subtract the inverse of the focal length from the inverse of the object distance, then, take the inverse of the result.

## How to Calculate Image Distance?

The following example problems outline how to calculate Image Distance.

Example Problem #1:

- First, determine the object distance (in).
- The object distance (in) is given as: 4.

- Next, determine the focal length (in).
- The focal length (in) is provided as: 2.

- Finally, calculate the Image Distance using the equation above:

1/Di = 1/F – 1/O

The values given above are inserted into the equation below and the solution is calculated:

1/Di = 1/2 – 1/4 = 4 (in)

Example Problem #2:** **

For this problem, the variables needed are provided below:

object distance (in) = 6

focal length (in) = 2

This example problem is a test of your knowledge on the subject. Use the calculator above to check your answer.

1/Di = 1/F – 1/O** = ?**