YouTube thumbnail calculator
YouTube thumbnails are usually designed in a 16:9 frame. This page helps you scale that frame up or down without changing the composition.
Live preview follows the selected ratio.
Calculator
Choose a ratio, enter width or height, and the calculator fills the matching dimension while keeping the image or video proportional.
Use these sizes as starting points. Exact platform requirements can change, so treat the calculator as the proportional reference and check the final upload screen before publishing.
| Use case | Pixel size | Ratio |
|---|---|---|
| Recommended thumbnail | 1280 x 720 | 16:9 |
| Full HD thumbnail | 1920 x 1080 | 16:9 |
| Small preview | 640 x 360 | 16:9 |
| Shorts cover frame | 1080 x 1920 | 9:16 |
The table below updates when you choose a new ratio. It is useful for planning responsive images, thumbnails, and video exports.
| Width | Matching height | Size |
|---|
Use large readable text.
Keep the main subject visible at small sizes.
Design at 1280 x 720 or larger, then export down if needed.
This reference chart shows how common frames compare. Use it when deciding whether a creative should be wide, square, portrait, or ultrawide.
