AI Image Size & Aspect Ratio Calculator
Pick an aspect ratio and a long edge to get pixel dimensions, then see which image models support that ratio and what a generation costs on HiAPI.
Pixel dimensions
- Width
- 1024
- Height
- 576
- Megapixels
- 0.59
Size: 1024×576
Exact ratio at this size.
Models that support 16:9
Supported ratios, sizes and prices by model
Ratios and sizes come from each model's current input options. Matching a ratio does not guarantee that a model accepts the calculated pixel dimensions; check its size limits in the docs. Prices show the current range across published options, not a quote for the calculated size.
| Model | Aspect ratios | Sizes | Price per image | Model docs |
|---|---|---|---|---|
| GPT Image 2 | — | 1024x1024, 1536x1024, 1024x1536 | $0.030 – $0.060 | Model docs |
| GPT Image 2 Ext | 1:1, 3:2, 2:3 | — | $0.007 – $0.760 | Model docs |
| FLUX.2 KLEIN 4B | 1:1, 4:3, 3:4, 16:9, 9:16, 3:2, 2:3, 21:9 | 0.25MP, 0.5MP, 1MP | $0.0004 – $0.0014 | Model docs |
Prices are a planning reference; the final charge follows the request and your account group.
How to choose an image size
- 01
Pick the aspect ratio
Match the ratio to where the image will be used: 1:1 for avatars, 16:9 for video thumbnails and banners, 9:16 for stories and phone wallpapers.
- 02
Set the long edge
Larger images show more detail but cost more and take longer. Start at 1024 px and go up only when you need print or high-DPI quality.
- 03
Check model support
Not every model accepts every ratio or size. The table shows what each model's current options allow, with a link to its docs.
AI image size calculator FAQ
How do I convert an aspect ratio to pixels?
Fix the long edge, then compute the short edge as long edge × the smaller ratio side ÷ the larger side. For 16:9 at 1024 px, the height is 1024 × 9 ÷ 16 = 576 px.
Why are dimensions rounded to multiples of 16?
Many image models require width and height divisible by 8 or 16. The calculator rounds to 16 and shows how far the rounded size drifts from your ratio.
Does a bigger size cost more?
Often yes. Many models price by resolution or quality tier, so the table shows a price range per model. Open the model page for the exact price of each option.
Which sizes does each model support?
The table is built from each model's current input options on HiAPI, so it stays in line with what the API accepts. Some models take named sizes such as 1K or 2K instead of pixels.
Is anything uploaded when I use this tool?
No. The calculation runs in your browser. Only the model list and prices are loaded from HiAPI.