📶 带宽与下载时间计算器Bandwidth Calculator
在文件大小、带宽（网速）和传输时间之间互算：例如 5 GB 文件在 100 Mbps 下要下载多久，或者 1 小时内传完 50 GB 需要多大带宽；可设置网络开销，区分 MB 与 MiB、Mbps 与 MB/s。Work out download time, required bandwidth or transferable data from the other two — how long 5 GB takes at 100 Mbps, or what speed moves 50 GB in an hour — with protocol overhead and proper MB vs MiB and Mbps vs MB/s handling.
使用说明与常见问题How-to & FAQ
「带宽与下载时间计算器」是什么？What is the Bandwidth Calculator tool?
在文件大小、带宽（网速）和传输时间之间互算：例如 5 GB 文件在 100 Mbps 下要下载多久，或者 1 小时内传完 50 GB 需要多大带宽；可设置网络开销，区分 MB 与 MiB、Mbps 与 MB/s。Work out download time, required bandwidth or transferable data from the other two — how long 5 GB takes at 100 Mbps, or what speed moves 50 GB in an hour — with protocol overhead and proper MB vs MiB and Mbps vs MB/s handling.
如何使用「带宽与下载时间计算器」？How do I use the Bandwidth Calculator tool?
在「带宽与下载时间计算器」中，填写「求解」、「文件大小」、「大小单位」、「带宽」、「带宽单位」等参数，结果会随输入实时计算并显示在下方。In the Bandwidth Calculator: Fill in "Solve for", "File size", "Size unit", "Bandwidth", "Bandwidth unit"; results are recalculated instantly as you type.
Mbps 和 MB/s 有什么区别？Mbps vs MB/s?
Mbps 是每秒兆比特，MB/s 是每秒兆字节，1 字节 = 8 比特，所以 100 Mbps 约等于 12.5 MB/s。宽带套餐通常用 Mbps，下载软件常显示 MB/s。Mbps is megabits per second and MB/s megabytes per second; 1 byte = 8 bits, so 100 Mbps is about 12.5 MB/s. Broadband plans quote Mbps; download managers often show MB/s.
GB 和 GiB 有什么区别？GB vs GiB?
GB 是十进制（10⁹ 字节），GiB 是二进制（2³⁰ = 1,073,741,824 字节）。Windows 显示的“GB”其实是 GiB，所以同一文件看起来更小。GB is decimal (10⁹ bytes) and GiB binary (2³⁰ = 1,073,741,824 bytes). Windows labels GiB as "GB", which is why the same file looks smaller there.
网络开销填多少？What overhead should I use?
TCP/IP 包头、加密和重传会占用部分带宽，实际速度会比标称带宽低一些；按经验可先填 5–10%（示例值，不是测量结论），Wi-Fi 下可能更多，最好用实测速度校准。TCP/IP headers, encryption and retransmissions eat some capacity, so real speeds are somewhat below the plan; 5–10% is a reasonable starting guess (an example default, not a measured figure), more on Wi-Fi, and a measured speed test is better.
需要联网吗？Does it need an internet connection?
不需要。「带宽与下载时间计算器」的解析和计算都在浏览器本地完成，不会向任何服务器发送请求。No. The Bandwidth Calculator parses and calculates entirely in your browser and sends no network requests.
「带宽与下载时间计算器」免费吗？需要注册吗？Is the Bandwidth Calculator free? Do I need an account?
「带宽与下载时间计算器」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Bandwidth Calculator is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.