Format calculator
The free format calculator converts pixels to millimetres, calculates aspect ratios and shows DIN formats and social media image sizes for print, Instagram, YouTube and LinkedIn.
Calculate aspect ratio
Enter width and height; the ratio is shown in simplified form.
Height for a ratio
Choose the width you want and a ratio; the matching height is calculated.
Pixels and millimetres
For print, resolution matters: at 300 dpi, 1000 pixels correspond to about 85 mm.
Size comparison
Every rectangle is drawn in the right proportion to the others.
- A0841 × 1189 mm
- A1594 × 841 mm
- A2420 × 594 mm
- A3297 × 420 mm
- A4210 × 297 mm
- A5148 × 210 mm
- A6105 × 148 mm
- Instagram Post (quadratisch)1080 × 1080 px
- Instagram Post (Hochformat)1080 × 1350 px
- Instagram Story / Reel1080 × 1920 px
- YouTube-Thumbnail1280 × 720 px
- LinkedIn-Banner1584 × 396 px
- Facebook-Beitragsbild1200 × 630 px
DIN formats (portrait)
| Format | mm | px at 300 dpi |
|---|---|---|
| A0 | 841 × 1189 | 9,933 × 14,043 |
| A1 | 594 × 841 | 7,016 × 9,933 |
| A2 | 420 × 594 | 4,961 × 7,016 |
| A3 | 297 × 420 | 3,508 × 4,961 |
| A4 | 210 × 297 | 2,480 × 3,508 |
| A5 | 148 × 210 | 1,748 × 2,480 |
| A6 | 105 × 148 | 1,240 × 1,748 |
Social media formats
| Format | px | Ratio |
|---|---|---|
| Instagram Post (quadratisch) | 1080 × 1080 | 1:1 |
| Instagram Post (Hochformat) | 1080 × 1350 | 4:5 |
| Instagram Story / Reel | 1080 × 1920 | 9:16 |
| YouTube-Thumbnail | 1280 × 720 | 16:9 |
| LinkedIn-Banner | 1584 × 396 | 4:1 |
| Facebook-Beitragsbild | 1200 × 630 | 40:21 |
Guide values. Platforms change their sizes – check them in the settings of each app before uploading.
What you can use Format calculator for
- Prepare print files: convert pixels to millimetres and check the right resolution of 300 dpi.
- Find social media image sizes: design for Instagram, YouTube, LinkedIn and Facebook with the right dimensions.
- Determine aspect ratios: calculate image formats such as 16:9, 4:5 or 1:1 and find heights for a fixed width.
- Look up DIN formats: A0 to A6 in millimetres and as pixel sizes at 300 dpi at a glance.
Frequently asked questions
What resolution do I need for print?
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For sharp prints, 300 dpi is usually the rule. Screens use 72 dpi as a reference, where pixels remain the real unit. The format calculator shows both side by side.
How do I convert pixels to mm?
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Divide the number of pixels by the dpi value and multiply by 25.4. At 300 dpi, 1,000 pixels correspond to about 84.7 mm. Simply enter the values above, the conversion runs automatically.
What is the difference between an aspect ratio and a format?
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The aspect ratio only describes the relation of width to height, for example 16 : 9. A format such as A4 also fixes dimensions in millimetres.
Why is my social media image cropped?
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Platforms display images in fixed ratios. Choose the image size intended for the respective post type before you design. Instagram posts and stories, for example, use different dimensions.
Are the social media image sizes up to date?
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They are guide values. Platforms change their requirements regularly, so check the dimensions in the respective app before uploading.
Which DIN formats are there?
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The DIN A series ranges from A0 at 841 × 1189 mm to A6 at 105 × 148 mm. Each step halves the previous format, and the ratio stays the same.