Bandwidth Calculator

Nobody sizes a link at 100% utilisation.

Nobody sizes a link at 100% utilisation. Link capacity for a user count, concurrency and per-user rate, with explicit headroom.

Written and maintained by Mohit PatelLast checked August 4, 2026How we build these

Total users

Bandwidth per active user

Mbps

Active at once

Headroom

Active hours per day

Link capacity needed

429 Mbps

60 concurrent users · A gigabit link covers this

Capacity needed428.6 Mbps (0.429 Gbps)

Concurrent users60

Per user5 Mbps

Headroom30%

Peak factor1.429×

Monthly data32.88 TB

RecommendationA gigabit link covers this

Real links are not sized at full utilisation. Above roughly 70%, queueing delay rises sharply — that is a result from queueing theory rather than a vendor rule of thumb — so the headroom is an explicit input here rather than a hidden multiplier. Concurrency is where estimates usually go wrong, in both directions. A busy office might see 30% of users generating traffic at once; a video-heavy environment can approach 100% in short bursts and idle almost completely between them. The monthly data figure matters when the link is metered rather than flat-rate. Cloud egress, mobile backhaul and satellite links are all charged by volume, and a comfortably-sized link can still produce an uncomfortable bill.

How the Bandwidth Calculator works

Link capacity for a user count, concurrency and per-user rate, with explicit headroom. Above roughly 70% utilisation queueing delay rises sharply, which is why the headroom is an input rather than a hidden multiplier.

Also known as: how much bandwidth do i need · mbps per user for an office · internet speed for 200 users · network capacity planning

Where to go next

The Bandwidth question rarely arrives on its own. These are the ones that usually come with it:

Download Time Calculator — Bits and bytes differ by eight. That is the whole trap.
Data Transfer Cost Calculator — Egress is where cloud bills go wrong.
IP Subnet Calculator — Handles /31 and /32 properly, which most do not.
Speed Distance Time Calculator — Any one of the three from the other two, in four units.

Sources

Frequently asked questions

How much bandwidth do I need per user?

Roughly 1 to 2 Mbps for browsing and email, 3 to 5 for video calls, and 5 to 25 for streaming depending on resolution. The concurrency assumption matters more than the per-user figure.

Why leave headroom?

Because queueing delay rises sharply above about 70% utilisation. That is a result from queueing theory rather than a vendor rule, and it is why a link running at 95% feels broken while showing capacity to spare.

What concurrency should I assume?

A busy office might see 30% of users generating traffic at once. Video-heavy environments approach 100% in short bursts and idle almost completely between them, which makes averages misleading.

Does upload matter as much as download?

More than it used to. Video calls, cloud backup and remote desktop are all upload-heavy, and asymmetric connections that look generous on paper often bottleneck on the upstream.

What about the monthly data figure?

It matters when the link is metered — cloud egress, mobile backhaul, satellite. A comfortably-sized link can still produce an uncomfortable bill if the charging is by volume.

Put this calculator on your own site

Free to use, on any site, commercial or not. Paste this where you want it to appear. It is a plain iframe, so it works in WordPress, Squarespace, Wix, Webflow, Ghost and anything else that accepts HTML.

The one-line version

<iframe src="https://www.thecalclibrary.com/embed/bandwidth-calculator" width="100%" height="640" style="border:1px solid #e2e8f0;border-radius:12px" loading="lazy" title="Bandwidth Calculator"></iframe>
<p style="font:13px/1.5 system-ui,sans-serif;margin:6px 0 0;color:#64748b">Powered by <a href="https://www.thecalclibrary.com/bandwidth-calculator" style="color:#64748b">Bandwidth Calculator</a> from The Calc Library</p>

The only condition is that the credit line below the frame stays in place. That one line is what pays for the tool being free — it is how anyone else finds it.