Free video tool
Aspect ratio calculator for video
Choose a ratio and enter one dimension. The calculator returns an even-pixel width and height you can use for recording, editing, or export.
16:9 with even-pixel dimensions. The calculated height is 1080px.
What the result means
Aspect ratio describes the shape of a frame, not its sharpness. A 16:9 frame could be 1280×720, 1920×1080, or 3840×2160. This calculator keeps the shape constant while changing pixel dimensions. It rounds to an even number because common video codecs and chroma-subsampling formats behave more predictably with even dimensions.
Formula or method
height = width × ratio height ÷ ratio width. When height is the known value, width = height × ratio width ÷ ratio height.
Boundaries to remember
- Cropping a source to a new ratio removes content; scaling it only changes resolution.
- Platform recommendations change, so verify upload limits before a campaign export.
- A larger resolution does not improve a low-resolution source.
Use the result
From calculation to a cleaner recording
Pick the destination first
Use 16:9 for standard landscape video, 9:16 for vertical stories or shorts, 1:1 for square placements, and 4:3 when the source or presentation requires it.
Enter the dimension you control
If the channel specifies a width, calculate height. If your source is constrained by height, switch the calculator and derive width.
Record in the final shape when possible
Framing the capture correctly avoids a late crop. Rekort includes common aspect-ratio controls and presentation backgrounds so the app window can sit inside the final canvas.
Questions
What is the aspect ratio of 1920×1080?
1920×1080 simplifies to 16:9. It is commonly called 1080p or Full HD.
What resolution is 9:16?
1080×1920 is a common 9:16 resolution. 720×1280 and 2160×3840 have the same shape at different pixel densities.
Should video dimensions be even numbers?
It is a safe default. Many codecs and pixel formats divide frames into blocks, and even dimensions avoid avoidable encoder compatibility problems.
Does changing aspect ratio reduce quality?
Changing the ratio usually means cropping or adding space. Cropping removes pixels; upscaling invents additional pixels and cannot restore source detail. Adding a background preserves the original capture.
Can I choose an aspect ratio before recording in Rekort?
Yes. Rekort's presentation controls include common aspect ratios plus background, padding, rounded-corner, and shadow options around the captured screen.
Put the answer into the recording.
Rekort records screen, webcam, system audio, and microphone on macOS, then adds auto-zoom, timeline corrections, backgrounds, and local MP4 or GIF export.