电动折叠伸缩门主要有门体、驱动器、控制系统构成的，它的尺寸计算方式除了要确定宽度和高度之外，电动折叠伸缩门的长度也是非常重要的一个方面，而且长度和电动折叠伸缩门价格相关联。
The electric folding telescopic door mainly consists of the door body, driver, and control system. In addition to determining the width and height, the length of the electric folding telescopic door is also a very important aspect, and the length is related to the price of the electric folding telescopic door.
最后一点，做了门洞的，还要计算门折叠缩起来的长度，这就是涉及到伸缩比率，每一款门的规格不一样，折叠伸缩比都是不一样的，尺寸规格越大，缩起来的长度就越长，如果计划做门洞的话，建议要先选好门型，再根据厂家算的折叠缩起来的长度来做门洞。厂家一般在做电动折叠伸缩门报价的时候都会计算好伸缩比的。
Finally, if you have made a door opening, you also need to calculate the length of the folding and shrinking of the door. This involves the expansion ratio. Each door has different specifications and the folding and shrinking ratio is different. The larger the size, the longer the shrinking length. If you plan to make a door opening, it is recommended to first select the door type and then make the door opening based on the manufacturer's calculated folding and shrinking length. Manufacturers usually calculate the expansion ratio when quoting for electric folding retractable doors.