0.5
Decimal ratio
the exact vertical inverse of 2:1 with double-height framing
1 : 2
1:2 Aspect Ratio Calculator
The complete 1:2 reference for tall mobile ads, extended portrait layouts, vertical posters, and elongated responsive cards. Calculate exact dimensions, compare 1:2 with 9:16 and 2:3, and copy CSS-ready output for very tall frames.
Tall mobile adsExtended portrait layoutsVertical poster systems
200%
CSS padding value
the exact legacy fallback for a 1:2 vertical container
2:1
Landscape counterpart
rotate the canvas and you arrive at the panoramic 2:1 frame
Calculate 1:2 Dimensions
Move between tall vertical sizes, mobile ad layouts, and CSS-safe output
Use exact 1:2 math for extra-tall portrait containers, poster-style layouts, mobile ad creative, and long-scroll visual modules. Switch modes to calculate or verify dimensions before export.
Enter a known width and the calculator derives the exact matching height.
×
Pixel mode uses the native output dimensions directly.
Quick 1:2 resolutions
Current Output
600 × 1200 px
The output stays locked to exact 1:2 math, including a CSS padding fallback of 200%.
Ratio
1:2
Decimal
0.5
CSS Padding
200%
Diagonal
1342 px
Switch to verify mode to check whether any existing file, crop, or export is exact 1:2 or only approximate.
Resolution Reference
Common 1:2 resolutions for tall mobile and vertical layout workflows
These sizes cover practical 1:2 use cases, from compact tall cards to large portrait masters and ad-ready vertical exports.
UI
UI and lightweight delivery
Useful for tall responsive cards, app modules, and low-weight mockups.
MOBILE
Mobile and ad delivery
Balanced sizes for tall mobile placements, posters, and extended portrait creative.
MASTER
High-resolution portrait masters
Larger working files for premium poster art, tall storytelling, and reusable master assets.
Why 1:2 Matters
Why 1:2 is the tall edge of common digital design
1:2 matters when 9:16 and 2:3 are not tall enough. It is one of the most elongated vertical formats that still appears in practical digital design, especially in mobile ad systems, tall product narratives, and poster-like responsive modules.
Because the height is exactly double the width, 1:2 creates a distinctly different reading rhythm from 9:16. The composition becomes more stacked, more sequential, and less cinematic. The viewer reads top to bottom rather than simply focusing on one centered subject.
That is why this ratio is best treated as a deliberate layout choice, not just a rotated crop. It is most useful when the content itself benefits from extra vertical runway.
Common Sizes
The 1:2 dimensions people actually use when a frame must stay very tall
The most practical 1:2 outputs include 400×800, 600×1200, 800×1600, and 1080×2160. Smaller versions are useful for design systems and app modules, while the larger sizes work for tall ads, posters, and detailed portrait storytelling.
Because the frame is so tall, source selection matters more than arithmetic. Wide or even normal portrait images often struggle to fill a 1:2 container without aggressive top-and-bottom narrative planning.
For that reason, 1:2 usually works best when the layout is designed specifically for it rather than derived as an afterthought from a standard camera frame.
Use Cases
The workflows where 1:2 is the right extra-tall portrait format
1:2 is most useful when the frame itself needs to feel elongated, stacked, and sequential rather than just portrait-oriented.
📱
Tall mobile ads
Some mobile placements and branded story panels benefit from more vertical runway than 9:16 provides, especially when the design stacks several elements in sequence.
540×10801080×2160
🧾
Extended portrait layouts
1:2 works well for timeline-like cards, before-and-after stories, or layouts that need several vertically sequenced content blocks in one frame.
600×1200800×1600
🪧
Vertical poster systems
Poster-like digital graphics and menu-style portrait layouts can use 1:2 when the design needs more height and a clearer top-to-bottom read.
600×12001600×3200
🛍️
Tall ecommerce storytelling
Some product stories benefit from a very tall frame that can show headline, detail shot, and CTA in one single stacked composition.
400×8001080×2160
🎨
Art-direction experiments
When the goal is visual distinctiveness rather than native platform compliance, 1:2 gives designers a deliberately uncommon portrait canvas.
800×16001600×3200
🔄
Portrait counterpart to 2:1
If the system already uses 2:1 for wide landscapes, 1:2 is the natural vertical mirror for tall variations in the same visual family.
600×12001080×2160
CSS and Layout
Use 1:2 when the container should feel intentionally tall
The modern CSS expression is `aspect-ratio: 1 / 2`. For older fallback techniques, the padding-top value is exactly 200%, because the height is twice the width.
This ratio is especially useful in card systems, tall landing-page callouts, poster-like modules, and mobile storytelling components that need more vertical distance than 9:16.
Because the container is so tall, text density and image cropping need extra care. Leave enough white space and keep the primary focal area in the upper-middle portion of the frame.
Height from Width
H = W × 2
Example: 600 × 2 = 1200
Width from Height
W = H × 0.5
Example: 1600 × 0.5 = 800
CSS Padding
P = (2 ÷ 1) × 100 = 200%
Use `padding-top: 200%` for the legacy fallback
Copy-ready CSS
Modern `aspect-ratio` plus a padding fallback
.ratio-frame {
aspect-ratio: 1 / 2;
}
.ratio-frame--legacy::before {
content: "";
display: block;
padding-top: 200%;
}
/* Example output size: 600x1200 */Decision Guide
Choose 1:2 only when the design truly needs extra vertical runway
1:2 is not a casual default. It is a strong compositional decision that works best when the content is meant to read in stacked layers or occupy a very tall portrait frame.
Pick 1:2 if the destination is a tall ad, a poster-like module, or a mobile story panel that needs more height than 9:16 or 2:3 can comfortably provide.
Avoid it when the layout must match a platform-native video format, when the source image is already tight, or when the extra height would only create empty space without adding meaning.
Use 1:2 for
- ✓Tall mobile ad units
- ✓Stacked portrait storytelling
- ✓Poster-like digital layouts
- ✓Intentional design-system variations
Avoid 1:2 for
- ×Native 9:16 social video workflows
- ×Standard portrait photography crops
- ×Wide source images with little vertical headroom
- ×General-purpose web cards that need broad reuse
Compare Nearby Ratios
See how 1:2 differs from 2:3 and 9:16
1:2 is taller than the common portrait formats most teams ship every day. The nearby comparisons show exactly when that extra height becomes useful and when it becomes excessive.
2:3
1000×1500
0.6667
Best for: Pinterest, portrait print, general portrait imagery
Avoid for: Very tall stacked mobile layouts
9:16
1080×1920
0.5625
Best for: Short-form video, Stories, Reels, Shorts
Avoid for: Poster-like static systems that need more height
1:2
1080×2160
0.5000
Best for: Tall ads, stacked portrait modules, experimental layouts
Avoid for: General native social video
How To
How to calculate or verify a 1:2 aspect ratio
- 1
Choose the known side
Use either width or height as the anchor in the calculator.
- 2
Apply the double-height relationship
Multiply width by 2 to get height, or divide height by 2 to get width.
- 3
Check that the content can survive the tall frame
Verify that the source composition still makes sense in a very elongated portrait crop.
- 4
Copy the CSS or export dimensions
Use the exact ratio values in layout code and the verified pixel dimensions in the production export.
Frequently Asked Questions
Frequently asked questions about 1:2
Is 600×1200 a 1:2 ratio?
Yes. Divide both values by 600 and the frame reduces exactly to 1:2.
What CSS percentage matches 1:2?
The legacy padding-top fallback is 200%.
How is 1:2 different from 9:16?
1:2 is taller. It keeps only 50% width relative to height, while 9:16 keeps 56.25%, so the frame feels more elongated and stacked.
When should I use 1:2 instead of 2:3?
Use 1:2 when the design truly needs more vertical runway for stacked content or poster-like composition. Use 2:3 for more general portrait imagery.
Keep Exploring
Explore nearby ratios and workflows
→
2:3 Guide
Step back to the more common portrait print and Pinterest ratio when 1:2 feels too tall.
→
9:16 Guide
Use the native short-form video ratio for Stories, Reels, Shorts, and TikTok.
→
2:1 Guide
See the landscape counterpart if the system also needs panoramic horizontal variations.
→
Aspect Ratio Cheat Sheet
Return to the full ratio-first reference and platform lookup page.