Email Header Image Size
Calculate email header image dimensions for 600px templates and 2x retina exports.
Controls
Local image preview
Your image stays in your browser. We do not upload or store your file.
Download overlays are transparent guides only. Uploaded image previews stay in this browser.
Workspace preview
Safe-zone result
Email Header Image: working canvas 1200×400px, 1 overlay zones. Upload an optional local image to preview crop and UI risk.
| Check | Status | Detail |
|---|---|---|
| Minimum width | info | No minimum width listed for this spec. |
| Minimum height | info | No minimum height listed for this spec. |
| Recommended canvas | safe | 1200×400px vs 1200×400px target |
| Aspect ratio | safe | 0% ratio mismatch |
| Megapixels | info | 0.48MP; no MP limit listed. |
| File size | safe | 0MB vs maximum 1MB |
| Format | danger | Detected unknown; allowed: JPEG, PNG, GIF, WebP |
- Many email templates render around 600px CSS width; 1200px provides 2x density.
- Keep file size small for deliverability and load speed.
How to use this result
Start with the target surface: a printed size, a platform canvas, a marketplace image requirement, or a safe-zone overlay. Enter the real pixel dimensions or upload a local image when the tool supports it, then compare the result with the recommended size, ratio, file-size limit, and source note.
Use the copied output as a production checklist rather than as an approval guarantee. The calculator checks measurable dimensions and ratios, while final acceptance can still depend on compression, color, account settings, crop previews, platform policy, or printer-specific export instructions.
FAQ
Why use 1200px wide?
It gives 2x pixel density for a 600px-wide email template.
Should email images be huge?
No. Keep file size controlled for faster loading.
Related tools
Sources and limits
strong-secondary: Mailchimp email image design guidance. Last checked 2026-05-24.
Platform dimensions are centralized in data files. Every platform spec must include sourceConfidence, sourceUrl and lastCheckedAt. Official platform documentation overrides this tool when specifications differ.