Image Crop Area Calculator
Calculate retained pixels and area loss for a proposed crop.
Your inputs
Calculation results
Formula & assumptions
Retained fraction = crop pixels/original pixels; no image file is changed.
Values use the specified units. Calculations use floating-point arithmetic. Check input measurements and formula assumptions before applying the result.
Compare your scenarios
Save up to five results to compare changes side by side. Scenarios stay in this tab until you clear or reload it.
Using Image Crop Area Calculator
Calculate retained pixels and area loss for a proposed crop.
- Enter original width, original height, crop width, crop height using the units printed under each field.
- Choose Calculate, or enable live updates. Review the result labels and formula assumptions.
- Save scenarios to compare up to five variations, then copy the report or download JSON or CSV.
Example
Original width: 4000 pixels Original height: 3000 pixels Crop width: 3000 pixels Crop height: 2000 pixels Retained megapixels: 6 Retained area · percent: 50 Removed area · percent: 50
Questions & answers
What does Image Crop Area Calculator calculate?
Calculate retained pixels and area loss for a proposed crop.
Which units should I enter?
Original width uses pixels. Original height uses pixels. Crop width uses pixels. Crop height uses pixels. Convert values to these units before calculating.
Which formula does it use?
Retained fraction = crop pixels/original pixels; no image file is changed.
What does the included example show?
Original width: 4000 pixels; Original height: 3000 pixels; Crop width: 3000 pixels; Crop height: 2000 pixels. Result: Retained megapixels = 6; Retained area · percent = 50; Removed area · percent = 50.
Can I compare different settings?
Yes. Save a scenario, change the inputs and save another result. Up to five scenarios are compared in this tab; they disappear when you reload or leave.
Can I export the calculation?
Copy the JSON report or download JSON and CSV with inputs, result labels and numeric values. Processing uses local JavaScript; no calculation request is sent to our server. Displayed values use up to 10 significant digits; exports retain JavaScript numeric precision.
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