Four tools on one page. Find how long a file takes to download or upload (or work backwards to the speed or the amount of data), convert between bits, bytes, MB and GB, estimate how much bandwidth a website needs from its page views, and convert a monthly data allowance into a steady speed in Mbps or back.
Choose what you want to find.
Type the size, speed or page views and pick the units.
Read the answer and the related figures.
Use the tables below to compare connection types.
Bits and bytes: 1 byte = 8 bits; 1 MB = 8 Mb
Download time: Time = file size (in bits) ÷ speed (bits per second)
Website bandwidth: Page views × page size ÷ seconds in the period × safety factor
Monthly data to speed: Speed = data in bits ÷ 26,29,800 seconds (an average month)
The bandwidth calculator answers the everyday questions about internet speed and data. How long will this file take to download? How many megabytes is that in gigabytes? How fast a line does my website need? How much data will a 10 Mbps link carry in a month? Choose the question, fill in two or three numbers, and the answer appears with its working.
Most confusion in this subject comes from two look-alike units. Speed is sold in megabits per second, written Mbps, but files are measured in megabytes, written MB. A byte is eight bits, so the two differ by a factor of eight. The calculator always shows both, so you can see why a 100 Mbps fibre plan downloads at about 12.5 MB every second. Students of networking, people comparing broadband plans and anyone running a website will find it useful.
1. Write the file size in bits. Multiply megabytes by 8 to get megabits.
2. Write the speed in bits per second, for example 5 Mbps is 50,00,000 bits per second.
3. Divide the size by the speed. The answer is the time in seconds.
4. Divide by 60 for minutes, and by 60 again for hours.
5. For a website, multiply page views by page size and divide by the seconds in the period.
6. Multiply by a safety factor of 2 or more to cover busy hours.
A bit is the smallest piece of data, a single 0 or 1. Eight bits make one byte, which is enough to hold one letter. Network speeds have always been counted in bits per second, while storage has been counted in bytes. So a speed of 8 megabits per second moves exactly 1 megabyte each second. In writing, a small b means bits and a capital B means bytes; mixing them up gives answers that are eight times too big or too small.
The speed printed on a broadband plan is the most the line can carry. What you get depends on many things: the Wi-Fi signal in your room, how many people at home are streaming, how busy the provider's network is, and how fast the server sending the file is. Each data packet also carries address and checking information, which uses up a few per cent of the line. Expect real downloads to run at 70 to 90 per cent of the plan.
A website that sends 1000 GB in a month uses only about 3 Mbps if the load is spread perfectly evenly. But visitors do not come evenly. Most arrive in a few busy hours, and search-engine bots add more. The line must handle the busiest moment, not the average. That is why planners multiply the average by a safety factor, and why hosting companies quote both a monthly data limit and a port speed.
Kiran in Vijayawada has a 40 Mbps broadband plan and wants to download a 2 GB lecture video before his online class.
Change the file size to bits (1 byte = 8 bits): 2 GB = 16000000000 bits
Change the speed to bits per second: 40 Mbps = 40000000 bits per second
Time = size ÷ speed: 16000000000 ÷ 40000000 = 400 seconds = 6 minutes 40 seconds
Answer: Time needed 6 minutes 40 seconds; Speed in megabytes per second 5 MB/s; Data moved in one minute 300 MB
Treating Mbps and MB/s as the same thing. Divide Mbps by 8 to get MB/s.
Forgetting that upload speed is often much lower than download speed on home plans.
Sizing a website line on average traffic and ignoring busy hours.
Mixing 1000-based GB with the 1024-based figure shown by Windows.
Expecting the full plan speed over weak Wi-Fi.
Estimating download or upload time for large files and backups.
Comparing broadband or mobile data plans.
Choosing a hosting plan from expected page views.
Changing a monthly data allowance into a line speed for a leased line or server.
Networking lessons and exam questions on data rate.
Why is my download speed in MB/s lower than my plan in Mbps?
They are different units. Mbps counts bits and MB/s counts bytes. Divide Mbps by 8 to get MB/s, so a 100 Mbps plan gives about 12.5 MB/s at best.
How many MB per second is 100 Mbps?
12.5 MB per second. Divide the Mbps figure by 8, because one byte is eight bits. In the same way 40 Mbps is 5 MB/s and 300 Mbps is 37.5 MB/s.
Can I find my real speed from a download I just did?
Yes. Tap Speed under Find the, then enter the file size and how long it took. A 700 MB file that took 4 minutes was coming in at about 23 Mbps.
How much data can I download in one hour?
Tap Data moved, then enter your speed and 1 hour. At 10 Mbps a line can move 4.5 GB in an hour.
How long will a 1 GB file take on a 50 Mbps connection?
1 GB is 8000 megabits. 8000 ÷ 50 = 160 seconds, which is about 2 minutes 40 seconds.
Is 1 GB equal to 1000 MB or 1024 MB?
Internet and hosting companies use 1000. Windows and many phones count in steps of 1024 but still write GB, which is why a 64 GB pen drive shows about 59.6 GB. The correct name for the 1024 version is GiB.
How much bandwidth does my website need?
Multiply the page views by the average page size, divide by the seconds in that period, then multiply by a safety factor of 2 or more, because visitors do not arrive evenly through the day.
What does 1000 GB per month mean in Mbps?
About 3.04 Mbps if the data flows evenly all month. Real traffic comes in peaks, so the line needs to be several times faster than this average.