Website Bandwidth & Storage Calculator
Work out how much disk space your site needs and how much bandwidth your traffic will actually use each month — before your host bills you for it.
How it works
Everything runs in your browser. Nothing you type is uploaded or stored.
What your site stores
CSS, JS, fonts, PDFs, downloads
Each full backup costs the same again in disk space.
Your traffic
Not sure? Measure a real page with the Webpage Size Checker.
Returning visitors re-download less. 30-50% is typical.
Share of traffic the CDN answers without touching your server.
Search engines and scrapers on top of human traffic.
Your host's pricing (optional)
Enter the rates from your own provider's pricing page. We deliberately don't bundle vendor prices — they change constantly and stale numbers are worse than none.
Results
| Pageviews per month | 25,000 |
| Before cache & CDN | 48.8 GB |
| Daily average | 1.2 GB |
| Busiest day (est.) | 3.0 GB |
| Sustained throughput | 115 Kbps |
| Transfer in 12 months | 65.5 GB |
What's taking up the space
If growth holds at 5% a month
| Month | Visitors | Transfer |
|---|---|---|
| 3 months | 11,576 | 42.3 GB |
| 6 months | 13,401 | 48.9 GB |
| 12 months | 17,959 | 65.5 GB |
| 2 years | 32,251 | 117.7 GB |
These are planning estimates, not a bill. Real usage swings with traffic spikes, how aggressively you cache, and whether your host measures compressed or uncompressed bytes. Leave headroom.
Storage and bandwidth are not the same bill
Storage is what your site is — every file sitting on disk, measured once. Bandwidth is what your site does — every byte shipped to a visitor, counted again on every single request. A 500 MB site can move 500 GB a month, and a 50 GB media library can move almost nothing if nobody watches the videos. Hosts price the two separately, and running out of one tells you nothing about the other.
The trap is that bandwidth scales with popularity while storage doesn't. Publishing a hundred new articles barely moves your disk usage. Getting one of them onto the front page of a news aggregator can multiply your transfer for the month. This is why capacity plans built around disk space alone tend to fail at exactly the moment things start going well.
Why your real usage differs from the raw multiplication
Pageviews times page weight is the starting point, not the answer. Three things pull the number in different directions, and this calculator lets you set all three:
Browser caching pulls it down. A first-time visitor downloads your CSS, JavaScript, fonts, and logo. The same person on their fourth page that session downloads almost none of it again. If a meaningful share of your traffic is returning readers, the raw multiplication overstates your transfer badly.
A CDN moves it somewhere else. Offloading doesn't reduce what visitors download — it changes who pays for it. Your origin server goes quiet while the CDN bill absorbs the volume. That's why the results show both figures: total transfer is what a bandwidth cap counts, and origin transfer is what your own server actually handles.
Bots push it back up. Search crawlers, uptime monitors, feed readers, and scrapers never appear in your analytics, because analytics runs JavaScript and most bots don't. On a small site with few humans, automated traffic can be a surprisingly large slice of the bytes leaving your server.
Getting a page weight worth trusting
Every number here depends on average page weight, and guessing it is where most estimates go wrong. Measure a real page instead — the Webpage Size Checker fetches a URL with a cold cache and adds up what actually transfers, which is the same basis this calculator works on.
Measure more than one. A text article and a photo gallery on the same site can differ by an order of magnitude, and your busiest pages matter far more than your typical ones. If a handful of heavy pages take most of your traffic, weight your average toward those rather than averaging the whole site evenly.
One caveat worth knowing: if your server sends assets with gzip or Brotli compression, the transferred size is already smaller than the raw files on disk. That means your storage figure and your bandwidth figure legitimately use different numbers for the same file, and neither is wrong.
Frequently asked questions
How much bandwidth does a typical website need?
It depends almost entirely on page weight, not page count. A text-heavy blog at 500 KB a page serving 10,000 monthly visitors moves roughly 10-15 GB. Swap in large images at 3 MB a page and the same traffic moves 60-90 GB. Measure your own pages rather than trusting a general figure.
What's the difference between total transfer and origin transfer?
Total transfer is everything your visitors download, which is what a hosting bandwidth cap counts. Origin transfer is only the part your own server sends after a CDN has answered what it could from cache. If you're on a plan with a transfer limit, watch the total; if you're sizing a server, watch the origin figure.
Should I include backups in my storage estimate?
Yes, if they live on the same disk or the same billed account. Each full backup is another complete copy of your content, so keeping three of them means paying for four times your actual site. Backups stored off-site with a different provider should be counted against that provider instead.
Why is my host reporting more bandwidth than my analytics suggest?
Analytics only counts visitors who run JavaScript. Search crawlers, uptime monitors, RSS readers, security scanners, and scrapers all consume real bandwidth while remaining invisible to your analytics. On smaller sites this automated traffic is routinely 10-30% of total bytes, which is what the bots setting accounts for.
Does this calculator send my numbers anywhere?
No. Every calculation runs in your browser using plain arithmetic. Nothing is uploaded, logged, or stored, and the page works offline once loaded.
Why does it not compare hosting providers for me?
Provider pricing changes often, and a stale comparison baked into a page is worse than none at all. Enter the rates from your own provider's current pricing page in the optional cost fields and the estimate will use those instead.