Video Letterbox Planner
Calculate contain-fit video size and bars in a target canvas.
Your inputs
Calculation results
Formula & assumptions
Contain scale = min(canvas width/source width, canvas height/source height).
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 Video Letterbox Planner
Calculate contain-fit video size and bars in a target canvas.
- Enter source width, source height, canvas width, canvas 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
Source width: 1920 pixels Source height: 1080 pixels Canvas width: 1080 pixels Canvas height: 1080 pixels Rendered width · pixels: 1080 Rendered height · pixels: 607 Left bar · pixels: 0 Right bar · pixels: 0 Top bar · pixels: 236 Bottom bar · pixels: 237
Questions & answers
What does Video Letterbox Planner calculate?
Calculate contain-fit video size and bars in a target canvas.
Which units should I enter?
Source width uses pixels. Source height uses pixels. Canvas width uses pixels. Canvas height uses pixels. Convert values to these units before calculating.
Which formula does it use?
Contain scale = min(canvas width/source width, canvas height/source height).
What does the included example show?
Source width: 1920 pixels; Source height: 1080 pixels; Canvas width: 1080 pixels; Canvas height: 1080 pixels. Result: Rendered width · pixels = 1080; Rendered height · pixels = 607; Left bar · pixels = 0; Right bar · pixels = 0; Top bar · pixels = 236; Bottom bar · pixels = 237.
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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