What this calculator does
Every input on this aspect ratio calculator maps to a real decision, so the output is something you can act on immediately, not a rough ballpark you'll have to double-check elsewhere.
Maintains proportion when resizing.
How to use the Aspect Ratio Calculator
- Enter your input.
- The result updates automatically.
- Copy or share the result.
The formula
newH = newW × h / w
Worked example
1920×1080 scaled to 1280 width → 720 height (16:9).
Common mistakes
- Ignoring rounding
- Wrong original ratio
- Non-uniform scaling
When to use it
Use for image resizing, video, design.
Pro tips for the Aspect Ratio Calculator
- Save your favorite scenarios by clicking the star icon — they're stored locally, no account needed.
- For big decisions, run best-case, expected, and worst-case scenarios and compare the breakdowns side by side.
- Copy the result to paste it directly into email, Notion, or a spreadsheet cell.
Frequently asked questions
›16:9?
Standard HD/4K video.
›4:3?
Older TV format.
›1:1?
Instagram square.
›9:16?
Vertical mobile / TikTok.
›Simplify ratio?
Divide both by GCD.
›Where does the formula come from?
The formula shown in the "How it works" section is the same one you'll find in standard developer & utility references — no proprietary tweaks or hidden weightings.
›Can I use this on mobile?
Yes — the aspect ratio calculator is fully responsive, and results, charts, and the share button all work on phones and tablets.
Embed this calculator
Drop the Aspect Ratio Calculator into your own site or blog post. Free to use — a small “Powered by CalcPilot” link is appreciated.
<iframe src="https://calcpilot.tools/calculators/aspect-ratio-calculator?embed=1" width="100%" height="720" style="border:1px solid #e5e7eb;border-radius:12px;max-width:720px;" loading="lazy" title="Aspect Ratio Calculator — CalcPilot"></iframe>Related calculators
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