Bandwidth Calculator guide
Bandwidth Calculator: Download Times and Data Use
Use our bandwidth calculator to work out download and upload times, how much data you use, or the broadband speed you need.
By the AllCalculator editorial teamUpdated 16 October 20261 min read
How long will that game take to download? Is my broadband fast enough? Our Bandwidth Calculator answers these questions without the bits-and-bytes headache.
How to use the calculator (Bandwidth Calculator)
Choose what to work out:
- Download or upload time: from the file size and your speed.
- Data used in a time: from your speed and how long.
- Speed needed: from the file size and how long you want it to take.
Bits and bytes
Broadband speeds are measured in megabits per second (Mbps), but file sizes are in megabytes (MB) or gigabytes (GB). There are 8 bits in a byte, so:
| Broadband speed | Downloads about |
|---|---|
| 10 Mbps | 1.25 MB a second |
| 70 Mbps | 8.75 MB a second |
| 500 Mbps | 62.5 MB a second |
| 1 Gbps | 125 MB a second |
A worked example
With the calculator's default settings, downloading a 50GB game at 70 Mbps takes about 1 hour 35 minutes. Real downloads are often 10% or more slower because of overheads and other traffic.
Frequently asked questions
Why is my download slower than my broadband speed?
Wi-Fi, other devices on your network, busy times of day and the server you're downloading from can all slow things down. Try a wired connection for the best speed.
What's the difference between GB and GiB?
A GB is 1,000,000,000 bytes. A GiB is 1,073,741,824 bytes (2³⁰). Some computers show sizes in GiB but label them GB.
How much speed do I need?
Under the UK's broadband Universal Service Obligation, everyone can request a connection of at least 10 Mbps, which is enough for basic use. Households that stream HD or 4K video on several devices at once need much more.
Sources and further reading
Links open official and independent websites in a new tab.
This guide is general information to help you understand your options. It isn't financial, tax, legal or building advice and doesn't take your personal circumstances into account. Figures were checked when the guide was last updated and can change, so confirm anything important with GOV.UK, HMRC, a regulated adviser or a qualified tradesperson.