Object Distance (m) Enter distance using sign convention (negative for real objects)

Focal Length (m) Enter focal length (negative for concave, positive for convex)

Quick Examples:

Concave Mirror (Real Image) Convex Mirror (Virtual Image)

Calculate Clear

This calculator is an estimation tool. Results should be verified with official sources for important decisions. It is based on standard physics formulas and may not account for all real-world optical imperfections.

What Is Image Distance

Image Distance is the space between the mirror and the spot where the image forms. It tells you exactly where the picture appears after light bounces off the mirror. This number helps you understand if the image is in front of the mirror or behind it. It is a key part of studying how light and mirrors work together.

How Image Distance Is Calculated

Formula

To find the image distance, we rearrange the formula to solve for v. We subtract the object distance part from the focal length part. Then, we flip the result to get the final distance. This math shows how the curve of the mirror changes where the light rays meet up.

Why Image Distance Matters

Knowing the image distance helps you set up optical tools correctly. It ensures that images are sharp and clear when you use mirrors or lenses.

Why Sign Convention Is Important for Correct Answers

Using the correct sign for each number is very important. If you mix up positive and negative signs, the math will give you the wrong answer. This tool uses a standard sign rule where light direction matters. Always check if your mirror is concave or convex before entering the focal length.

For Concave Mirrors

Concave mirrors curve inward like a bowl. They often form real images that can be projected onto a screen. This calculator helps you find where that screen should go. The result usually appears on the same side as the object for real images.

For Convex Mirrors

Convex mirrors curve outward like the back of a spoon. They always make virtual images that look smaller and behind the mirror. This type of mirror is good for seeing a wide view. The calculation will show a positive image distance for these mirrors.