Pixel density estimates how tightly pixels are packed. At the same viewing distance and size, higher PPI usually produces finer text edges.
√(width² + height²) ÷ diagonalDual-monitor decision tool
Compare monitor sharpness, scale, workspace, and link demand
PPI alone does not decide whether a monitor is good for coding. Compare two exact configurations, including the scale you expect to use and the refresh rate your dock must carry.
Display A
Display B
Interpret the numbers
Five metrics that change a coding-monitor decision
The physical distance between pixel centers. A smaller pitch corresponds to higher density.
25.4 mm ÷ PPITwo monitors can have the same diagonal but different aspect ratios. Calculated width and height help with desk fit and side-by-side planning.
The calculator divides native pixels by the selected UI scale. This is a planning estimate, not a promise of a specific macOS HiDPI mode.
Resolution × refresh × 24 bits gives a lower-level comparison of link demand before blanking, encoding overhead, color depth, chroma, or DSC.
Common profiles
What changes between 27-inch 1440p, 27-inch 4K, and 32-inch 4K
| Profile | Approx. PPI | Typical planning scale | Decision value | Connection check |
|---|---|---|---|---|
| 27-inch 1440p | 109 | 100-125% | More native workspace at modest link demand, with visibly lower text density than 4K at the same size. | Usually easier for older USB-C and dock paths. |
| 27-inch 4K | 163 | 150-200% | Higher text density with a choice between larger UI and more logical workspace. | Verify the exact dock, cable, and monitor input preserve the intended refresh rate. |
| 32-inch 4K | 138 | 125-150% | Larger physical workspace and a less aggressive scaling requirement, but needs more desk depth. | Same 4K link demand as 27-inch 4K at the same refresh. |
| 27-inch 4K 120Hz | 163 | 150-200% | Sharper motion and text scrolling, with roughly double the raw pixel payload of 4K60. | Requires host, dock, cable, adapter, and input support; do not infer it from “4K” alone. |
The calculation cannot measure
- Panel contrast, brightness, subpixel layout, uniformity, motion response, or coating.
- Whether macOS exposes the exact HiDPI mode you prefer without another tool.
- Viewing comfort, stand ergonomics, text rendering preference, or return experience.
Verify the complete connection path
- MacBook native display limit and whether the dock uses Thunderbolt, DisplayLink, or MST.
- Cable direction, adapter type, DisplayPort/HDMI version, DSC, color depth, and monitor input mode.
- USB-C power delivery, KVM or hub bandwidth sharing, firmware, and sleep/wake behavior.
Practical questions
Is 27-inch 4K always better than 27-inch 1440p for coding?
No. It usually offers higher text density, but the better fit depends on scaling preference, GPU and dock path, refresh target, price, and whether your software looks good at the chosen logical workspace.
Does the bandwidth estimate tell me which cable to buy?
No. It is a raw comparison value. Real links add transport overhead and may use DSC or different color formats. Match every component to the monitor manufacturer's and dock manufacturer's documented mode.
Why can two 4K monitors behave differently through the same dock?
They may use different inputs, EDID data, color depth, refresh modes, cables, or adapters. A dock can also route each output through a different video technology. Diagnose the entire path, not only the panel resolution.