Free · no signup · MB, GB or TB
Download Time Calculator
Enter a file size and your connection speed to see how long the download will take. The math divides the size in megabits by your speed in megabits per second — the calculator handles the bits-versus-bytes conversion for you.
Short answer
Download time = file size ÷ speed, after converting both to the same unit: a plan sold as 100 Mbps moves at most 12.5 MB per second (there are 8 bits in a byte). So a 10 GB file at 100 Mbps takes about 13 minutes, and a 100 GB game about 2 hours 13 minutes. Enter your own size and speed below.
Download time (best case)
13 min 20 sec
- Transfer rate
- 12.5 MB/s
- Assumes full speed sustained
- 100 Mbps
About the download time calculator
The formula is seconds = (size in GB × 8,000) ÷ speed in Mbps. Real downloads run a little slower than the plan's headline number — server limits, WiFi overhead and other traffic all take a cut — so treat the result as a best case and round up for planning.
Internet speed needed by activity
| Activity | Speed needed | Per |
|---|---|---|
| Web browsing & email | 1 Mbps | device |
| Music streaming | 1 Mbps | stream |
| HD video streaming (1080p) | 5 Mbps | stream |
| 4K video streaming | 25 Mbps | stream |
| HD video calls (Zoom, Meet) | 4 Mbps | call |
| Online gaming | 4 Mbps | player |
| Smart home devices & cameras | 2 Mbps | device |
Figures are per simultaneous stream, call or device — add them up for everything your household does at once, then add ~30% headroom for WiFi overhead and peaks. Sources: FCC broadband guide, Netflix and Zoom requirements.
Download time by file size and connection speed
| File size | 25 Mbps | 100 Mbps | 300 Mbps | 1,000 Mbps |
|---|---|---|---|---|
| 1 GB | 5 min 20 sec | 1 min 20 sec | 27 sec | 8 sec |
| 5 GB | 26 min 40 sec | 6 min 40 sec | 2 min 13 sec | 40 sec |
| 10 GB | 53 min 20 sec | 13 min 20 sec | 4 min 27 sec | 1 min 20 sec |
| 20 GB | 1 hr 46 min | 26 min 40 sec | 8 min 53 sec | 2 min 40 sec |
| 50 GB | 4 hr 26 min | 1 hr 6 min | 22 min 13 sec | 6 min 40 sec |
| 100 GB | 8 hr 53 min | 2 hr 13 min | 44 min 27 sec | 13 min 20 sec |
| 150 GB | 13 hr 20 min | 3 hr 20 min | 1 hr 6 min | 20 min |
Best-case times: seconds = (GB × 8,000) ÷ Mbps. Server limits, WiFi overhead and other traffic add to these.
How we calculate this
Three simple formulas, with the bits-versus-bytes conversion handled for you:
- Speed you need. each activity's per-stream requirement × how many run at once, summed, then multiplied by 1.3× headroom and rounded up to the next common plan tier.
- Download time. the file size converted to megabits (1 GB = 8,000 megabits) divided by your speed in Mbps gives seconds.
- Mbps ↔ MB/s. there are 8 bits in a byte, so MB/s = Mbps ÷ 8. A 100 Mbps plan downloads at most 12.5 MB per second.
Assumptions
- Per-activity figures are published service requirements (Netflix, Zoom) and the FCC's consumer guide — real bitrates vary by app and quality setting.
- File sizes use decimal units (1 GB = 1,000 MB), matching how stores and operating systems label downloads.
- Download times are best-case: they assume the connection sustains its full speed for the whole transfer.
- The 30% headroom covers WiFi overhead, bitrate peaks and background traffic; a congested or distant router can lose more than that.
Sources
Last reviewed: July 21, 2026
Frequently asked questions
How much internet speed do I need?+
Add up what your household does at the same time: about 5 Mbps per HD stream, 25 Mbps per 4K stream, 4 Mbps per video call or gaming player, and 1–2 Mbps per browsing or smart-home device. Then add ~30% headroom, because WiFi rarely delivers the plan's full speed and streams peak above their average. For most families that lands between 100 and 300 Mbps — the calculator does the math for your exact mix.
Is 100 Mbps fast?+
Yes, for most households. 100 Mbps meets the FCC's fixed-broadband benchmark (raised to 100/20 Mbps in 2024) and carries four 4K streams' worth of bandwidth, or two 4K streams plus calls, browsing and smart-home traffic with headroom. It feels slow mainly for very large downloads — a 100 GB game still takes over two hours.
What is the difference between Mbps and MB/s?+
Mbps is megaBITS per second — the unit internet plans are sold in. MB/s is megaBYTES per second — the unit your browser shows during downloads. There are 8 bits in a byte, so divide by 8: a 100 Mbps plan downloads at most 12.5 MB/s. This mix-up is why downloads often look "8× slower" than the plan you pay for.
Why is my WiFi slower than the speed I pay for?+
Plans are quoted for a wired connection to the modem; WiFi loses speed with every wall, floor and metre between you and the router, and shares the air with every device in the house. Old routers, the crowded 2.4 GHz band, and busy evening hours cut throughput further. Testing next to the router on 5 GHz usually recovers most of the headline number — if it doesn't, the problem is upstream of your WiFi.
How long does it take to download a 100 GB game?+
100 GB is 800,000 megabits, so at 100 Mbps it takes about 2 hours 13 minutes, at 300 Mbps about 44 minutes, and at 500 Mbps about 27 minutes — all best-case numbers, since store servers and WiFi overhead usually add time. The download-time pages on this site show common sizes from 1 GB to 150 GB at every typical plan speed.
What internet speed do I need for 4K Netflix?+
Netflix lists 15 Mbps as the minimum for 4K, and 25 Mbps per 4K stream is the safe planning figure most providers use. Remember it is per screen: two 4K TVs at once need ~50 Mbps just for the video, before anything else in the house. For 1080p HD, plan about 5 Mbps per stream.
What internet speed do I need for gaming?+
Only about 4 Mbps per player to actually play — but low latency matters far more than bandwidth. Aim for a ping under 50 ms and use a wired connection where you can. Where a fast plan does help is downloads: modern games are 50–150 GB, so moving from 100 Mbps to 500 Mbps turns a two-hour install wait into under half an hour.
Also try the WiFi Speed Calculator.