How much bandwidth do I need?
Enter your daily visitors, pages per visit and average page size. The bandwidth calculator shows the data your site sends each month and day, and the average speed in Mbps that carries it.
- Data transfer per month (GB)
- 180
1,000 visitors a day at 3 pages of 2 MB need 180 GB a month, an average of 0.556 Mbps.
- Data transfer per day (GB)
- 6
- Average speed (Mbps)
- 0.556
- Page views per month
- 90,000
Data transfer per month (GB): 180. 1,000 visitors a day at 3 pages of 2 MB need 180 GB a month, an average of 0.556 Mbps.
Data transfer per month (GB) by visitors a day
How to calculate
Works out a website’s monthly data transfer (bandwidth) from its daily visitors, pages per visit and page size, and the average connection speed in Mbps that carries it.
Example with the default inputs (Visitors a day 1,000, Pages per visit 3, Average page size 2 MB, Days in the month 30, Margin factor 1): 1,000 visitors a day at 3 pages of 2 MB need 180 GB a month, an average of 0.556 Mbps.
Method: Monthly bytes = visitors a day × pages per visit × page size × days × margin factor. GB = bytes ÷ 10⁹. Average Mbps = bytes × 8 ÷ (days × 86,400 s) ÷ 10⁶.
- Every page view sends the full page size; browser caching, which lowers repeat views, is not counted.
- Traffic is spread evenly over the day; the average speed is not the peak a server must handle.
- GB means 10⁹ bytes and Mbps 10⁶ bits per second; 1 byte is 8 bits.
Worked examples
Each example is checked against the calculator on every build.
- Visitors a day 1,000, Pages per visit 3, Average page size 2 MB, Days in the month 30, Margin factor 1 gives Data transfer per month (GB) 180, Data transfer per day (GB) 6, Average speed (Mbps) 0.555556, Page views per month 90,000.Source: NIST, Metric (SI) prefixes (kilo 10³, mega 10⁶, giga 10⁹, tera 10¹²), https://www.nist.gov/pml/owm/metric-si-prefixes (retrieved 2026-10-05)
- Visitors a day 25,000, Pages per visit 4.2, Average page size 1.5 MB, Days in the month 31, Margin factor 1.5 gives Data transfer per month (GB) 7,323.75, Average speed (Mbps) 21.875.Source: NIST, Metric (SI) prefixes (kilo 10³, mega 10⁶, giga 10⁹, tera 10¹²), https://www.nist.gov/pml/owm/metric-si-prefixes (retrieved 2026-10-05)
- Visitors a day 500, Pages per visit 2, Average page size 0.8192 MB, Days in the month 30, Margin factor 1 gives Data transfer per month (GB) 24.576.Source: 500 × 2 × 30 × 819,200 = 24.576 × 10⁹ bytes (NIST binary prefixes, https://physics.nist.gov/cuu/Units/binary.html, retrieved 2026-10-05)
How it works
page views per month = visitors a day × pages per visit × days
monthly bytes = page views per month × page size (bytes) × margin factor
- Data transfer per month (GB) = monthly bytes ÷ 10⁹
- Data transfer per day (GB) = the monthly figure ÷ days
- Average speed (Mbps) = monthly bytes × 8 ÷ (days × 86,400 seconds) ÷ 10⁶
Units
- Page size: kB (10³ bytes), MB (10⁶), GB (10⁹), KiB (2¹⁰ = 1,024 bytes) or MiB (2²⁰ = 1,048,576 bytes).
- GB in the answer means 10⁹ bytes. Mbps means 10⁶ bits per second; 1 byte is 8 bits.
Rules
- Visitors and pages per visit must be above 0; the page size is at least 1 byte; days are a whole number from 1 to 31; the margin factor is from 1 to 100.
- Every step is exact on the numbers as typed; the monthly figure is shown to 2 decimals, the daily figure and the speed to 3.
- Page views per month do not include the margin factor.
Worked examples by hand
1,000 visitors, 3 pages, 2 MB, 30 days, factor 1. Views = 1,000 × 3 × 30 = 90,000. Bytes = 90,000 × 2,000,000 = 1.8 × 10¹¹ = 180 GB a month, 6 GB a day. Speed = 1.8 × 10¹¹ × 8 ÷ (30 × 86,400) ÷ 10⁶ = 1.44 × 10¹² ÷ 2,592,000 ÷ 10⁶ = 0.556 Mbps.
25,000 visitors, 4.2 pages, 1.5 MB, 31 days, factor 1.5. Views = 25,000 × 4.2 × 31 = 3,255,000. Bytes = 3,255,000 × 1,500,000 × 1.5 = 7.32375 × 10¹² = 7,323.75 GB. Speed = 7.32375 × 10¹² × 8 ÷ 2,678,400 ÷ 10⁶ = 21.875 Mbps.
500 visitors, 2 pages, 800 KiB, 30 days. 800 KiB = 819,200 bytes. 500 × 2 × 30 × 819,200 = 2.4576 × 10¹⁰ bytes = 24.576 GB.
Other questions people ask
How do I calculate website bandwidth?
Multiply visitors a day by pages per visit by the average page size, then by the days in the month. 1,000 visitors a day viewing 3 pages of 2 MB each send 6 GB a day, or 180 GB in a 30-day month. Multiply by a margin factor, such as 1.5, to leave room for peaks.
How do I find my average page size?
Open the page in a browser, open the developer tools, and look at the Network tab: it shows the total data transferred for the page. Use an average over your most visited pages, with images, scripts and styles included.
What is the difference between bandwidth and data transfer?
Hosting plans often say "bandwidth" for the total data sent in a month, in GB or TB. Strictly, bandwidth is a rate, in Mbps. The calculator shows both: the monthly total and the average rate that would carry it.
Why does the margin factor matter?
Traffic is not even. Busy hours, a post that goes viral, search engine bots and file downloads all add to the average. A factor above 1 plans for this; with 1.5 the page shows half as much again as the plain average.
Is the average Mbps the speed my server needs?
No, it is the floor. It spreads the month’s data evenly over every second, but most traffic comes in a few busy hours. The peak speed a server must handle is several times the average.
Does caching lower the bandwidth?
Yes. Browsers keep images, scripts and styles, so a visitor’s second and later pages send less. A content delivery network also serves files from its own servers. The calculator counts every page at full size, so its answer is an upper estimate.