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Calcimator

Lens Equivalent Calculator

Convert focal lengths between camera sensor sizes. Find the equivalent field of view and crop factor when switching between camera systems.

Inputs

mm

Results

Equivalent Focal Length

25 mm

Conversion Factor

2

Full-Frame Equivalent50 mm
Source Crop Factor1
Target Crop Factor2
Field of View (source)46.8°
Field of View (target)46.8°
Lens Category (FF equiv)Normal / Standard
How to Use This Calculator
  1. Enter Focal Length, Source Sensor (lens is on), and Full Frame (36x24mm).
  2. Set APS-C Canon (22.3x14.9mm), APS-C Nikon/Sony (23.5x15.6mm), and Micro Four Thirds (17.3x13mm).
  3. Adjust 1-inch (13.2x8.8mm), 1/2.3-inch (6.17x4.55mm) as needed.
  4. Review Equivalent Focal Length (mm) and Conversion Factor.
  5. Use Full-Frame Equivalent (mm) and Source Crop Factor to inform your decision.

How the result changes with Focal Length

Focal LengthEquivalent Focal LengthConversion Factor
201100.3 mm2
701349.9 mm2
1,300648.9 mm2
1,800898.5 mm2

What each input means

Focal Length
The focal length of the lens you want to convert.
Source Sensor (lens is on)
The sensor size of the camera the lens is currently on.
Target Sensor (convert to)
The sensor size you want to find the equivalent focal length for.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    Focal Length = 50, Source Sensor (lens is on) = 1, Target Sensor (convert to) = 4 = 3 input(s) provided
  2. Calculate Equivalent Focal Length
    Equivalent Focal Length
    25 = 25
  3. Calculate Conversion Factor
    Conversion Factor
    2 = 2
  4. Calculate Full-Frame Equivalent
    Full-Frame Equivalent
    50 = 50
  5. Calculate Source Crop Factor
    Source Crop Factor
    1 = 1

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