Many proxy plans are priced by the gigabyte, so it pays to estimate how much you'll use before you buy.
The calculation
Traffic is roughly the number of requests, times the average size of each response, plus a margin for requests you have to repeat.
traffic = requests × average response size × (1 + retry rate)
For example, 100,000 requests at an average of 300 KB each is about 28.6 GB. If one request in ten has to be repeated, add 10%: about 31.5 GB.
Find your real page size
Open the page in your browser, open the developer tools, and look at the Network tab. It shows the size of everything the page loads. A plain HTML page can be small, while a full page with images, scripts and fonts can be several megabytes.
Ways to use less
- Ask for data, not pages. If the site has a JSON endpoint behind the page, that response is usually much smaller than the full page.
- Block images, video and fonts if you use a headless browser and don't need them.
- Allow compressed responses by sending an Accept-Encoding header.
- Don't fetch the same page twice: keep what you've already collected.
Buying
Round up and leave room. A small first purchase lets you measure real usage before you commit to a large plan. Providers may count a gigabyte slightly differently, so check how yours does.
The Proxy Usage Calculator does this sum for you, including retries.
Try it: Proxy Usage Calculator — Turn requests and page size into the proxy traffic you will need.