Magnification Calculator
Calculate magnification factor from object and image sizes.
Results
Magnification is simply the ratio of image size to object size. A magnification of 5× means the image is 5 times larger than the object. Values less than 1 indicate reduction. This calculator is used in microscopy, photography, projection systems and any optical system where you need to know how much an image is enlarged or reduced.
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Frequently asked questions
The image is 5 times larger than the object. A 10 mm specimen appears as 50 mm in the image. That is a 400% enlargement from the original size.
Divide image size by object size. If a 2 mm cell appears as 200 mm under a microscope, magnification = 200/2 = 100×. The cell appears 100 times its actual size.
Light microscopes: 40× to 1000×. A 10× eyepiece with a 40× objective gives 400× total magnification. Electron microscopes reach 50,000× to 1,000,000×.
A standard 50 mm lens on full-frame (36 mm sensor) gives about 0.15× at minimum focus. A macro lens reaches 1.0× (life-size). A 200 mm telephoto gives about 4× at the same distance.
Optical magnification uses lenses to create a larger image on the sensor. Digital zoom crops and enlarges pixels, reducing quality. 2× digital zoom halves the resolution, while 2× optical zoom maintains full resolution.