How to use this calculator?
- Enter your download speed. Use the average speed quoted for your package, or the result of a recent speed test if you want a more accurate answer.
- Enter your upload speed. On most UK packages this figure is far lower than the download speed, and it changes the answer considerably.
- Enter a file size, or choose one of the common files listed beneath the boxes.
The results update as you type. The real-world setting stays switched on by default, and it reduces both speeds to 85% of the figure you entered. That allowance reflects the way broadband actually behaves once protocol overheads, Wi-Fi and the limits of the server you are downloading from all come into play. Switch it off if you want the theoretical best case instead.
Beneath the results, you will find the same file compared across every common UK broadband speed, which shows how much time a faster package would save you on that particular download.
Download & upload time calculator
Enter your speeds and a file size to see how long the transfer really takes — in both directions.
Common files
↓ Time to download
—
↑ Time to upload
—
The same file on other UK connections
Download time only.
| Connection | Download speed | Time |
|---|
Times assume the file is the only thing using your connection. Real transfers are also limited by the server you are downloading from, your Wi-Fi, and how many other devices are active at the time.
Find the speed you need - Availability Checker
Frequently Asked Questions
How is download time calculated?
The calculation converts your speed from megabits into megabytes, then divides the file size by that figure. One byte contains eight bits, so a connection delivering 150Mbps moves 18.75 megabytes every second before any losses. Apply the 85% real-world allowance and that becomes 15.9 megabytes per second. A 1GB file contains 1,024 megabytes, so the download takes 1 minute 4 seconds. Uploads use the same method, but with your upload speed in place of your download speed.
Why isn't 100Mbps the same as 100MB per second?
Because the two use different units. Broadband speeds are quoted in megabits, and file sizes are quoted in megabytes. Dividing by eight converts one to the other, so a 100Mbps connection transfers 12.5 megabytes per second at best, and 10.6 megabytes per second once you allow for real-world losses. This single conversion explains most of the disappointment people feel when they watch a progress bar on a package they have just upgraded to.
How long does it take to download a 1GB file?
A 1GB file takes 1 minute 4 seconds on a 150Mbps connection with the real-world allowance applied. The same file takes 2 minutes 24 seconds on an average 67Mbps FTTC line, 19 seconds on a 500Mbps package and 10 seconds on a 900Mbps full fibre package. On an older ADSL line delivering an average 11Mbps, you wait 14 minutes 36 seconds for the same file.
How long does it take to download a 4K film?
A 4K film of 25GB takes 26 minutes 46 seconds on a 150Mbps connection. Move up to 500Mbps and the wait drops to 8 minutes 2 seconds. A 900Mbps full fibre package brings it down to 4 minutes 28 seconds, and a 2Gbps package finishes in 2 minutes. On an average 67Mbps FTTC line, the same film takes just under an hour, which is why 4K downloads feel painfully slow on part-fibre connections.
How long does it take to download a modern game?
An 80GB console game takes 1 hour 26 minutes on a 150Mbps connection and 14 minutes 17 seconds on a 900Mbps full fibre package. Larger titles reaching 150GB take 2 hours 41 minutes at 150Mbps and 26 minutes 46 seconds at 900Mbps. Game downloads are the clearest argument for a faster package, because file sizes have grown far quicker than the speeds most UK homes actually buy.
How long do common files take at each UK broadband speed?
| File | 11Mbps | 67Mbps | 150Mbps | 500Mbps | 900Mbps | 2Gbps |
|---|---|---|---|---|---|---|
| Photo album, 50MB | 43 sec | 7 sec | 3 sec | 1 sec | Under a second | Under a second |
| HD TV episode, 1.5GB | 21 min 54 sec | 3 min 36 sec | 1 min 36 sec | 29 sec | 16 sec | 7 sec |
| Film in 1080p, 4GB | 58 min 24 sec | 9 min 35 sec | 4 min 17 sec | 1 min 17 sec | 43 sec | 19 sec |
| Film in 4K, 25GB | 6 hr 5 min | 59 min 56 sec | 26 min 46 sec | 8 min 2 sec | 4 min 28 sec | 2 min |
| Console game, 80GB | 19 hr 28 min | 3 hr 12 min | 1 hr 26 min | 25 min 42 sec | 14 min 17 sec | 6 min 26 sec |
| Large game install, 150GB | 36 hr 30 min | 5 hr 59 min | 2 hr 41 min | 48 min 11 sec | 26 min 46 sec | 12 min 4 sec |
Why is my actual download slower than the figure shown?
The calculator assumes the file is the only thing using your connection, which is rarely true. Other devices in the home take a share of the bandwidth, your Wi-Fi may be the weakest link rather than the line itself, and the server sending you the file sets its own limit. Older laptops and phones also cap out below gigabit speeds, and a slow hard drive can restrict a large download before the connection does.
Why does the calculator use 85% of your speed?
Every connection loses a slice of its bandwidth to the overheads that keep data moving correctly, and no download ever reaches the full quoted figure. An 85% allowance produces a realistic answer for most UK homes on a wired connection. Switch the setting off and you get the theoretical maximum, which is useful for comparing packages against each other but optimistic as a guide to what you will actually see.
Does Wi-Fi slow down downloads?
Frequently, yes, and it becomes the main restriction on faster packages. A device connected on the 2.4GHz band rarely exceeds an average 60Mbps in a typical home, so a 900Mbps package delivers nothing close to its potential over that connection. The 5GHz band performs far better but weakens quickly through walls and floors. If you have paid for gigabit broadband, test your speed over an ethernet cable before blaming the provider.
Why do downloads slow down in the evening?
Between 8pm and 10pm, more homes in your area are online at once, and shared parts of the network carry their heaviest load. Full fibre copes with this far better than older technologies, because each premises has a dedicated fibre line to the local cabinet rather than a copper connection that weakens with distance. Cable and FTTC connections show the largest evening drop, particularly in densely populated areas.
Why is my upload speed so much slower than my download?
Most UK broadband is asymmetric, which means the connection reserves far more capacity for receiving data than sending it. A typical full fibre 150Mbps package comes with a fully 30Mb upload speed, so sending a file takes five times longer than receiving the same file. Providers configure networks this way because household internet use has always leaned heavily towards downloading, though cloud backups, video calls and home working have narrowed that gap considerably.
What is the difference between symmetric and asymmetric broadband?
A symmetric connection offers an upload speed equal to the download speed, so a 1Gbps package sends and receives at 1Gbps. An asymmetric connection offers a much lower upload figure. Openreach-based full fibre packages are asymmetric, offering an average 110Mbps upload speed on a 900Mbps package. Virgin Media cable packages are also asymmetric, with the Gig1 package offering an average 104Mbps upload speed alongside its 1130Mbps download speed.
Which UK providers offer symmetric upload speeds?
Several altnets build their networks with equal speeds in both directions. Hyperoptic, Community Fibre, YouFibre, toob, G.Network and B4RN all offer symmetric packages, and Gigaclear offers them on selected plans. None of the national providers using the Openreach network offer symmetric residential packages, so if you need fast uploads, availability depends entirely on whether one of these networks has reached your street.
How long does it take to back up 100GB to the cloud?
On a fully 30Mb upload speed, a 100GB backup takes 8 hours 55 minutes. On a Virgin Media M125 package offering an average 20Mbps upload speed, the same backup takes 13 hours 23 minutes. A 900Mbps full fibre package with an average 110Mbps upload speed completes it in 2 hours 26 minutes, and a symmetric gigabit package finishes in 16 minutes. This single comparison explains why upload speed matters more than most people expect.
What download speed do I actually need?
For streaming and browsing, an average 67Mbps FTTC line remains adequate for a couple or a small family. Large downloads change the answer entirely. If you regularly install games, download 4K films or move large work files, an average 150Mbps package saves hours every month, and 500Mbps or faster saves more again. Households with several heavy users at once benefit from a faster package even when no single device needs the extra bandwidth.
Will upgrading my broadband make every download faster?
No. Upgrading raises the ceiling, but only removes the restriction if your line was the slowest link. Streaming services already cap their bitrate, so a faster package will not improve picture quality. Small files finish so quickly that the difference is imperceptible. Large downloads from fast servers, cloud backups and game installs are where an upgrade delivers a significant improvement, and those are the tasks worth basing your decision on.
Is gigabit broadband worth it for downloads alone?
For most homes, no. Moving from an average 67Mbps line to an average 150Mbps package delivers the single biggest improvement, because it removes the long waits on everyday downloads. Going from 500Mbps to 900Mbps saves 3 minutes 34 seconds on a 4K film, which few households will notice. Gigabit packages earn their price in homes with many devices running at once, in households that upload large volumes of data, or where the upload speed on offer is considerably better than the alternatives.
Getting the speed you need
If the times above look too slow, the answer is a package with a faster download speed, a faster upload speed, or both. Work out which of the two is actually holding you back first, because the fastest download speed on offer is wasted money if your real problem is sending large files.
Availability is the next step, and it decides everything. Full fibre coverage in the UK varies street by street, so two homes a few doors apart can have entirely different options. Some areas have Openreach full fibre, a competing altnet and Virgin Media cable all available at once, while others still rely on an FTTC connection with an average 67Mbps download speed.
Our postcode checker gives you the answer in seconds. Enter your postcode and you will see every package available at your address, with the download speed, the upload speed and the monthly price for each one. You can then run those figures back through the calculator above to see exactly what each package would do for the files you actually download.
The checker also brings up our exclusive offers, which include discounts you will not find on providers' own sites, voucher codes, bill credit and reduced setup fees. These change regularly and vary by provider, so it is worth checking before you commit to any package.
Best Broadband Deals Checker
One final point before you switch: check the upload speed as carefully as the download speed. It is the figure providers promote least and the one most likely to disappoint you six months into a contract.
