Aspect Ratio Converter

Convert aspect ratios and resolutions for video and photo. Calculate missing width or height and simplify ratios (e.g. 3840×2160 → 16:9).

Input

Fill exactly two fields: Width + Height → ratio, Width + Ratio → height, Height + Ratio → width.
Ratio presets
Tip: After calculate, the result can be auto-copied (and you can still use the Copy button).

Results

Output —
Output is either the missing side (px) or a simplified ratio.

History

No calculations yet. Run one to store it here.

    Related Tools

    How Aspect Ratio Works

    Frame Shape = Storytelling

    Aspect ratio is simply the shape of your frame — the relationship between width and height (like 16:9, 1.85:1 or 2.39:1). It doesn’t change your lens perspective — it changes what the audience gets to see.

    In filmmaking, aspect ratio is a creative choice: it controls composition, negative space, and how “cinematic” or “intimate” the image feels.

    How This Converter Works

    Fill exactly two fields and the tool calculates the third:

    1. Width + Height → Ratio: simplifies a resolution into a clean ratio (example: 3840×2160 → 16:9).

    2. Width + Ratio → Height: keeps your width and computes the matching height (useful for timelines and exports).

    3. Height + Ratio → Width: keeps your height and computes the matching width (handy for social crops or delivery specs).

    Key Terms for the Crew

    Letterbox: black bars top/bottom when you fit a wider ratio into a narrower frame.

    Pillarbox: black bars left/right when a narrower frame sits inside a wider canvas.

    Crop: you’re throwing away pixels to match a target ratio — composition must be planned for it.

    Pro Examples

    The “Clean YouTube / TV Look”: 16:9

    Great for web delivery, tutorials, and modern TV. Safe framing, easy overlays.

    The “Classic Cinema”: 2.39:1

    Wide, epic, and very “film”. Also forces you to think in horizontal composition and blocking.

    DP Tip: If you know your delivery ratio (e.g. 2.39:1), compose for it on set — don’t “fix it in crop” later. Cropping is easy, but losing headroom or titles is not.