视频比例适配
UpBox优盒工具箱，免费在线视频比例适配：输入原始宽高与目标比例，直接给出裁剪后的尺寸、切掉多少、补边的画布与黑边厚度，横屏转竖屏前先算清楚。
无需注册 · 数据不上传No sign-up · nothing uploaded
原始画面Source
目标比例
已换算
裁剪是画面被切掉一部分、内容铺满，补边是画面完整但四周留边；平台通常只接受一种，发布前先确认目标比例，再决定用哪套数
换算结果Sizes
裁剪填满Crop to fill
补边留框Pad to fit
裁剪后
补边后
预览只是示意：外框是目标比例，蓝色区域是保留的内容；裁剪时蓝区铺满，补边时蓝区缩小、外面就是黑边
本工具所有运算在本地浏览器完成，你的文件、文本不会上传到服务器
工具介绍
把横屏视频发到竖屏平台，画面要么上下被切、要么两侧留黑，事先不知道会损失多少就只能赌。 Posting a landscape clip to a portrait feed either crops it or adds bars, and without numbers you are guessing how much is lost.
两套结果一起给：裁剪方案告诉你切多少、还剩多少内容；补边方案告诉你画布多大、黑边多厚。 Both answers come at once: cropping says what is cut and what remains, padding says how big the canvas is and how thick the bars are.
- 两组数据Two answers
- 七种比例Seven ratios
- 实时预览Live preview
- 损失占比Loss share
使用说明
- 填原始宽高。Enter the source size.
- 选目标比例。Pick the target ratio.
- 对比裁剪与补边。Compare crop and pad.
- 按方案去剪辑。Cut accordingly.
常见问题
裁剪是不是切掉两边？Does cropping always cut the sides?
看方向：原画面更宽时切左右，更高时切上下，输出始终居中，两边对称切。It depends: a wider source loses sides, a taller one loses top and bottom, and the result stays centred with symmetric cuts.
为什么尺寸都是偶数？Why are the sizes even?
编码器普遍要求宽高为偶数，奇数会被自动挪一位，所以这里直接向下取偶，省得后面再补。Most encoders want even dimensions and would shift an odd value anyway, so the result rounds down to even here.
2.35:1 这类比例怎么处理？What about 2.35:1?
按 235:100 精确计算，不会当成 21:9；两者宽度接近但留边厚度差一截。It is computed as 235:100, not rounded to 21:9, since the bar thickness differs noticeably.
能算帧数和码率吗？Can it do frame counts or bitrate?
不能，本页只管几何尺寸；码率与体积要看编码参数，另一页的码率估算更合适。No, this page is geometry only; bitrate and file size belong to the encoder settings and the size estimator covers that.