How download time is calculated
File sizes are measured in megabytes (MB) but internet speeds are quoted in megabits per second (Mbps), and there are 8 bits in a byte. So the formula is seconds = (file size in MB × 8) ÷ speed in Mbps. A 700 MB file on a 50 Mbps connection takes (700 × 8) ÷ 50 = 112 seconds, or 1 min 52 sec. Long transfers are easier to read in hours, which the minutes to hours calculator handles.
How to use this calculator
Enter the file size in megabytes and your connection speed in Mbps (the figure your internet plan advertises). The result is the estimated download time. Real downloads run a little slower than the theoretical figure because of overhead and shared bandwidth, so treat it as a best case. To plan reading once it lands, see the reading time calculator.
For context, typical broadband plans run 25 Mbps at the low end, 100–300 Mbps for a standard fibre or cable package, and 1,000 Mbps (1 Gbps) at the top. Older Wi-Fi hardware, a busy evening on a shared line, or a slow server can all cap you well below the number on your bill, so expect roughly 70–90% of the theoretical figure in practice. For short files, convert the answer with the seconds to minutes calculator.
Worked example
A 4,000 MB (4 GB) game on a 100 Mbps line: (4000 × 8) ÷ 100 = 320 seconds = 5 min 20 sec. Doubling your speed roughly halves the time. If you are downloading on a road trip, also budget the fuel with the gas cost calculator.
Frequently asked questions
- How do I calculate download time?
- Multiply the file size in MB by 8, then divide by your speed in Mbps. A 700 MB file at 50 Mbps takes 112 seconds.
- How long to download 700 MB at 50 Mbps?
- About 112 seconds, or 1 min 52 sec, in ideal conditions.
- Why multiply by 8?
- File sizes are in megabytes (MB) but speeds are in megabits (Mbps), and 1 byte equals 8 bits, so you convert MB to megabits.
- Why is my real download slower?
- Network overhead, congestion, Wi-Fi limits and the server can all reduce actual speed below your plan's rated Mbps.
- Is Mbps the same as MB/s?
- No, and confusing them is the most common mistake here. Mbps is megabits per second while MB/s is megabytes per second, and 1 MB/s equals 8 Mbps. A 100 Mbps plan therefore peaks at roughly 12.5 MB/s.