Here is how most people budget a scraping project.

They guess. They buy a plan that feels about right. Then three days in they discover the job needs four times the bandwidth they expected, and the conversation with whoever approves spending becomes awkward.

Chiproxies is not a proxy seller. It is a set of free browser based calculators that do the arithmetic before you spend anything, and I think it deserves a bookmark from anyone who runs this kind of work.

What the Calculators Cover

The tools handle the questions you should be asking before a project starts rather than during it. How many proxies a job actually needs. How much bandwidth a given page count will consume. How long a run will take at a given concurrency. What retries do to both the timeline and the bill. Where the cost optimisation opportunities sit.

Everything runs in the browser, with no account and nothing to install.

Why Retries Are the Number Everyone Forgets

Of all of these, the retry calculator is the one I would point people at first.

When you plan a scrape, you plan the happy path. Ten thousand pages, so ten thousand requests. In reality some fraction fails and gets retried, and if your success rate is eighty percent rather than the hundred percent you assumed, your actual request count is meaningfully higher than the plan.

That difference shows up in three places at once: bandwidth consumed, time taken, and money spent. People notice it in the invoice rather than in the plan, which is the wrong order.

Running the numbers first turns a surprise into a decision.

Sizing Before Buying

The proxy sizing calculator answers the question that causes the most waste in this industry: how many IPs do I actually need.

Buy too few and your job crawls, or worse, you hammer a small set of addresses until they get flagged. Buy too many and you are paying for capacity that sits idle.

The right number depends on your concurrency, your target's tolerance and your timeline, which is exactly the kind of relationship a calculator handles better than intuition.

How I Would Use It

Before you buy anything from anyone, spend ten minutes here. Estimate your page count, your average page size and your realistic success rate. Come out the other side with a bandwidth figure and an IP count.

Then go shopping with actual numbers instead of a feeling. You will buy a smaller plan than you were about to, and it will be the right one.

Once you have candidates, our proxy checker tells you whether the IPs you were sold are actually alive and responsive, which is the other half of the same question.

Who It Fits

Anyone planning a scraping or data collection project, teams who have to justify a budget before it is approved, and anyone who has ever blown through a bandwidth allowance faster than expected. It is also genuinely useful for people learning how this work is costed, because the calculators make the relationships visible.

Who Might Look Elsewhere

If you are running one small job with a handful of requests, the maths fits in your head and you do not need a tool for it.

And because this is a planning site rather than a provider, you will still need to buy proxies somewhere. Treat it as the step before shopping, not a replacement for it.

Final Verdict

Chiproxies is a small, free, genuinely useful set of tools in a market that mostly wants to sell you something.

Planning proxy usage properly is the single cheapest way to reduce what you spend on proxies, and these calculators make that planning take minutes rather than an afternoon of spreadsheet work. The retry calculator alone will save most people money the first time they use it.

Bookmark it, run your next project through it before you buy, and see how different the number looks from your guess.