Magnification Ratio Calculator
Calculate magnification ratio for macro photography
About this calculator
A magnification ratio calculator helps macro photographers determine the actual size relationship between a subject and its representation on the camera sensor. This tool calculates how many times larger or smaller your subject appears compared to its real-world size, expressed as ratios like 1:1, 2:1, or 1:2. Understanding magnification ratios is crucial for macro photography planning, lens selection, and achieving desired image compositions with precise scale measurements.
How to use
Enter the actual size of your subject and the size it appears on your camera sensor. The calculator will compute the magnification ratio automatically. You can input measurements in millimeters, centimeters, or inches. The result shows whether you're achieving true macro magnification (1:1 or greater) or close-up photography ratios.
Frequently asked questions
What is considered true macro magnification?
True macro photography begins at 1:1 magnification ratio, where the subject appears life-size on the camera sensor. Ratios like 2:1 or 3:1 represent higher magnification levels.
How do I measure subject size on the sensor?
Use your camera's viewfinder or LCD screen with grid lines, or measure the subject width in your final image and convert based on sensor dimensions.
What's the difference between 1:2 and 2:1 ratios?
1:2 means the subject appears half life-size on sensor (close-up), while 2:1 means the subject appears twice life-size (high magnification macro photography).