Estimate resized image size using clear inputs and transparent formulas, with results intended for planning and comparison.
How to use this calculator
For resized image size calculator, enter Original width, Original height, New width, New height, the remaining displayed fields using the unit or format beside each field. Select Calculate to apply the formula below, review all returned values together, and use Reset to restore the demonstrated inputs before testing another scenario.
Formula & calculation method
pixelCountRatio = 100*newWidth*newHeight/(originalWidth*originalHeight); estimatedResizedMb = originalSizeMb*newWidth*newHeight/(originalWidth*originalHeight); estimatedSavingMb = originalSizeMb*(1-newWidth*newHeight/(originalWidth*originalHeight))Worked example
For a reproducible resized image size calculator example, use Original width: 4000; Original height: 3000; New width: 2000; New height: 1500; plus the remaining displayed defaults. The first returned value, new-to-original pixel ratio, is calculated with 100*newWidth*newHeight/(originalWidth*originalHeight); the other results describe the same scenario. Change one input at a time and keep its unit consistent when comparing scenarios.
Limitations to keep in mind
Digital sizes, transfer volumes, memory, and costs are estimates under the entered conventions. Actual formats, compression, protocols, provider pricing, workload, and system overhead can differ.