DISPLAY WORKSHEET · FREE
CarPlay screen helper.
Know your display.
Calculate physical dimensions and compare resolution scaling before changing your display settings.
Your worksheet
Make the numbers useful.
Enter your dimensions and calculate physical size, scaling and a comparison checklist.
A geometry calculation and test worksheet, not a CarPlay layout simulator. It cannot predict iOS layout thresholds or decoding performance.
Change one thing at a time.
Physical size and layout
DiPlay’s reported Physical length can affect CarPlay layout. Calculated screen width is a measurement reference, not a mandatory value. iOS changes layouts at thresholds; small adjustments may produce no visible change.
Scaling and frame rate
80% of width and height means 64% of the original pixel count; 60% means 36%. Fewer pixels can reduce workload but do not guarantee smoother decoding. Compare 30 and 60 fps separately from resolution.
Edges and safe area
Save current values before changing safe-area options. A square-corners option can be useful where available, but cannot fix every display or firmware combination.
References: Reviewed DiPlay release notes · Troubleshooting guides
Screen dimensions and scaling: common questions
How do I calculate screen width in millimeters from inches and pixels?
Convert the active diagonal from inches to millimeters by multiplying by 25.4. Then multiply by pixel width divided by the square root of (pixel width squared + pixel height squared). Height uses the same formula with pixel height. PPI is the diagonal pixel count divided by the diagonal in inches. These calculations assume square pixels and a rectangular active area.
Does 80% resolution mean 20% fewer pixels?
No. Scaling both width and height to 80% leaves 64% of the original pixel count, or 36% fewer pixels. For example, 1920 × 720 becomes 1536 × 576. This is a mathematical estimate; application rounding, alignment and decoding performance may differ.
Should I enter the calculated width as DiPlay’s Physical length?
Treat it as a measurement reference, not a mandatory setting. Measure the lit display, exclude the bezel and save the current value first. Compare one available adjustment at a time; iOS layout thresholds mean a small change may have no visible effect. Follow the display troubleshooting guide on the Official Website.