Data transfer calculator
Enter a speed and a duration to see how much data moves in that time. The calculator also shows the most the connection could move running flat out for a day and for an average month.
Runs entirely in your browser. Nothing you type is sent anywhere.
How the amount is calculated
Data moved is rate multiplied by time, divided by 8 to turn bits into bytes:
GB = Mbps × seconds ÷ 8 ÷ 1,000
For example, 100 Mbps for 2 hours is 100 × 7,200 ÷ 8 ÷ 1,000 = 90 GB. The full-use figures apply the same formula to 86,400 seconds (one day) and 2,629,746 seconds (an average month of 30.436875 days). At 100 Mbps that is 1.08 TB a day and about 32.87 TB a month.
Worked examples
- A movie night in 4K. YouTube recommends 20 Mbps for 4K. Three hours at that rate is 20 × 10,800 ÷ 8 ÷ 1,000 = 27 GB, an upper bound since streams often run below the recommended connection speed.
- A live stream. Broadcasting at Twitch's 6,000 kbps (6 Mbps) for 4 hours uploads 10.8 GB. Streaming for that long five days a week adds up to 54 GB of upload a week.
- A cloud camera. If a camera uploads 2 Mbps around the clock (a common range is 1–2 Mbps while recording; our estimate), it sends 21.6 GB a day and about 657 GB in an average month, a large share of a 1,200 GB data cap on its own.
For household totals across many activities and hours, the data usage calculator adds them up and compares the result with a cap.
Assumptions and limits
The result assumes the rate holds for the whole duration. Real connections vary, and most activity is bursty: a 100 Mbps plan used for browsing moves far less than 90 GB in two hours because it sits idle most of the time. Treat the output as the maximum for that rate and time. Protocol overhead means the data a service counts can differ slightly from the bits on the line. Units are decimal: 1 GB is 1,000,000,000 bytes. If you compare the result with an operating system or router that reports GiB, the same amount shows as about 7% fewer units.
Data caps are the most common reason to run this calculation. A connection that is busy for only a few hours a day still adds up: 25 Mbps of streaming for 4 hours every day is 45 GB a day, or about 1.37 TB over an average month, more than a 1,200 GB cap.
Related calculations
To go the other way, from a monthly or daily volume to the steady speed needed, use TB to Mbps. To find how long a specific file takes, the download time calculator divides instead of multiplies. For website traffic built up from visitors and page size, see the bandwidth calculator.
Frequently asked questions
How much data does 100 Mbps use in an hour?
At full speed for the whole hour, 45 GB: 100 megabits × 3,600 seconds ÷ 8 = 45,000 MB. Actual use is usually much lower because connections are rarely busy the entire time.
How much data can a 1 Gbps connection transfer in a day?
At full use, 10.8 TB: 1,000 Mbps × 86,400 seconds ÷ 8 = 10,800,000 MB.
How much data does a 4K stream use in 3 hours?
At YouTube's recommended 20 Mbps, up to 27 GB. Netflix recommends 15 Mbps for 4K, which gives about 20.25 GB for the same 3 hours.