Bandwidth Calculator
Convert a data rate between bits and bytes per second (Mbps, MB/s, Gbps, MiB/s and more), or work out the monthly data transfer and bandwidth a website needs.
Result…
How it's calculated
bits per second = value × bits in one unit 1 byte = 8 bits · k, M, G, T = 1000, 1000², 1000³, 1000⁴ · Ki, Mi, Gi = 1024, 1024², 1024³ Monthly transfer = visits × pages per visit × page size Average bandwidth = monthly transfer × 8 ÷ seconds in a month · Peak = average × peak factor
Data rates are counted in bits a second for networks and in bytes a second for files, and a byte is 8 bits. The decimal prefixes (k, M, G, T) are powers of 1000 as defined by the SI, and the binary prefixes (Ki, Mi, Gi) are powers of 1024 as defined by the IEC, so 1 MiB/s is 1.048576 MB/s. For a website, the data sent in a month is the number of page views times the average page weight; spread over the seconds in an average month (365 ÷ 12 days) it gives the average rate, and the peak factor scales that up to the busiest moments, which is what a connection or server port must carry.
Your numbers, step by step
About the Bandwidth calculator
This bandwidth calculator does two things. First, it converts a data rate between bits and bytes per second in decimal units (kbps, Mbps, Gbps, kB/s, MB/s, GB/s) and binary units (Kibit/s, MiB/s, GiB/s), so you can see why a 500 Mbps plan downloads at about 62.5 MB/s. It also shows how much data that rate moves in an hour or a month and how long 1 GB takes. Second, it estimates what a website needs: the monthly data transfer from visits, pages per visit and average page size, and the average and peak bandwidth that traffic adds up to. Developers choosing a hosting plan, network admins sizing a link and anyone puzzled by a speed test will find it useful. Each step of the working is shown, with the unit definitions spelled out.
How to use it
- Choose what to “Work out”: “Convert a data rate” or “Bandwidth for a website”.
- To convert, enter the “Data rate” and pick the “From” and “To” units.
- For a website, enter the “Visits a month”, “Pages per visit” and “Average page size” in kB or MB.
- Set a “Peak factor” from your analytics for how far the busiest moments exceed the average.
- Read the monthly transfer, the average and peak bandwidth, and the daily figure.
Worked example
500 Mbps is 500 × 10⁶ bits a second; ÷ 8 = 62.5 MB/s, or 59.6 MiB/s. At that rate 1 GB takes 16 s and an hour moves 225 GB. A site with 120,000 visits a month, 2.5 pages per visit and 1.8 MB pages serves 300,000 page views and 540 GB a month (about 17.75 GB a day). Spread over the 2,628,000 seconds of an average month that is 1.64 Mbps on average, and with a peak factor of 4 the busiest moments need about 6.58 Mbps.
Updated
Questions people ask
How do I convert Mbps to MB/s?
Divide by 8, because a byte is 8 bits: 100 Mbps is 12.5 MB/s. For MiB/s, divide the bytes a second by 1,048,576 instead of 1,000,000.
What is the difference between MB and MiB?
MB (megabyte) is 1,000,000 bytes, using the SI prefix; MiB (mebibyte) is 1,048,576 bytes, using the IEC binary prefix. Some operating systems show MiB but label it MB, which is why a file can look smaller than its download size. The data storage converter converts file sizes the same way.
How do I calculate the bandwidth a website needs?
Multiply visits by pages per visit by the average page size to get the monthly transfer. Multiply by 8 and divide by the seconds in a month for the average rate in bits a second, then multiply by a peak factor for the busiest times.
Why is my download slower than my plan's speed?
Plans quote bits a second, while browsers usually show bytes a second, so divide by 8 before comparing. Protocol overhead, Wi-Fi, other devices and the server's own speed also take a share. The download time calculator estimates how long a file takes.
How reliable is the website estimate?
It is a planning figure. Caching, compression, bots, image sizes that differ by device and sudden traffic spikes all move the real number, and hosts measure transfer in different ways. Leave headroom above the peak and check how your host counts it.