18:9 Calculator (2:1 Univisium) — Phone Tall Display
18:9 tall phone display — flagship phones, phablets and modern “full view” panels at 2:1.
18:9 is 2:1 written in phone marketing — 2160×1080, 2880×1440 and many 6.5-inch panels normalize to 18:9 after rounding and corner radius. It is a convenient shorthand for the 2:1 tall family before 19.5:9/20:9 took over. Solve wallpapers and viewport reservations that honor rounded corners and punch-hole cutouts.
1920 × 960
Exact ratio: 2:1 · CSS: aspect-ratio: 18 / 9 · padding-top fallback: 50.00%
Formula
height = width × 9 ÷ 18
width = height × 18 ÷ 9
// padding-top fallback: 50.00% — keeps layout stable before the image loads
aspect-ratio: 18 / 9 — modern replacement for the padding hack
All math runs locally in your browser. No upload. Type either side, the other solves live — and the URL updates so you can share an exact pair (?w=1920&rw=18&rh=9) or bookmark a preset.
Common 18:9 resolutions
| Width | Height | Use |
|---|---|---|
| 320px | 160px | |
| 640px | 320px | |
| 1280px | 640px | |
| 1920px | 960px | |
| 2560px | 1280px | |
| 3840px | 1920px | 4K |
| 5120px | 2560px | |
| 7680px | 3840px |
When to use 18:9
- Tall phone wallpapers (2160×1080 class)
- Phablet viewports & responsive breakpoints
- Marketing sheets quoting 18:9
Pitfalls to avoid
- Actual phones are often 19.5:9 or 20:9 — 18:9 is the conservative safe master
- Corner radius and punch-hole eat pixels — keep content inset
CSS snippet
Modern:
.frame { aspect-ratio: 18 / 9; width: 100%; overflow: hidden; }
.frame > img { width: 100%; height: 100%; object-fit: cover; }Legacy padding hack (for very old browsers):
.wrap { position: relative; width: 100%; padding-top: 50.00%; }
.wrap > * { position: absolute; inset: 0; }Pair with object-fit: contain to letterbox without cropping, or cover to fill and crop safely.
Platform reference
Frequently asked
Is 18:9 the same as 2:1?
Yes: 18:9 reduces to 2:1. Same shape, just multiplied by 9.
What phones are 18:9?
Many 2017–2019 flagships were marketed 18:9 (2160×1080). Newer phones are taller — 19.5:9 or 20:9.
What wallpaper size for 18:9?
Use the panel-native size — e.g. 2160×1080 — rather than scaling a 16:9 wallpaper.
Tip: add ?w=1920 or ?h=1080 to this URL to prefill the calculator — useful for linking from a spec doc.
Other ratios
- 16:9 Aspect Ratio Calculator
- 4:3 Aspect Ratio Calculator
- 1:1 Square Calculator
- 9:16 Vertical Calculator
- 21:9 Ultrawide Calculator
- 3:2 Aspect Ratio Calculator
- 16:10 Aspect Ratio Calculator
- 4:5 Portrait Calculator
Look up by resolution
- 1920×1080 — 1920×1080 Full HD
- 1280×720 — 1280×720 HD
- 3840×2160 — 3840×2160 4K UHD
- 2560×1440 — 2560×1440 QHD
- 1366×768 — 1366×768 WXGA
- 3440×1440 — 3440×1440 UW-QHD
What aspect ratio is 1920×1080? → · Full FAQ →