How to estimate bandwidth needs

Quick answer: Estimate peak concurrent transfer, not monthly totals: simultaneous users × average object size ÷ acceptable load time. A content site rarely needs more than a fraction of a 1G port; video, backups, game downloads and busy APIs are what actually saturate links. Measure after launch with vnstat and upgrade if peaks approach the port speed.

Overview

Bandwidth is the speed of your connection at a moment; traffic is the volume per month (see the difference). Plans are sized by port speed, so what you must estimate is the busiest moment of your day, not the monthly sum.

Before you start

• Rough numbers: expected visitors/day, average page or file size, peak-hour share.
• Any heavy flows: backups, media, replication, API bursts.

Step-by-step guide

1. Web traffic: peak concurrent users × page weight ÷ tolerable load time. Example: 200 concurrent users × 2 MB page ÷ 2 s = 200 MB/s of bursts ≈ 1.6 Gbps peak — but real users don't click simultaneously; divide by a realistic overlap factor (5–10×), giving ~200–300 Mbps.
2. Downloads/media: concurrent downloads × per-user speed you want to guarantee. 100 users × 10 Mbps = 1 Gbps — here port speed genuinely matters.
3. Background flows: add nightly backups/replication; schedule them off-peak so they don't fight with users.
4. Add headroom: plan for 2× your estimate — growth and spikes are cheaper to absorb than outages.
5. Measure reality after launch:

   sudo apt install -y vnstat
   vnstat -h    # hourly profile
   vnstat -m    # monthly totals

Common issues

• Confusing monthly TB with port speed: 10 TB/month is only ~30 Mbps average — peaks are what hurt.
• Sizing for average instead of peak: your launch-day or campaign spike is the real requirement.
• Forgetting backups: an unscheduled 500 GB backup at noon will crowd out customers.

When to contact support

If your measured peaks regularly approach the port speed, request more bandwidth; for unusual patterns (streaming, game content), describe the workload and we'll suggest a fit.

Frequently asked questions

Do I size by monthly traffic or by peaks?

By peaks. Monthly volume translates to a tiny average rate; the busiest moment of your day is what must fit in the port speed.

How do I measure my real usage?

Install vnstat and check vnstat -h for hourly peaks and vnstat -m for monthly volume after a week of normal operation.

How much headroom should I plan?

Plan for about twice your estimated peak — traffic growth and unexpected spikes are much cheaper to absorb with headroom than with emergency upgrades mid-incident.

Related articles

• What is the difference between traffic and bandwidth?
• What does a 1G / 10G / 20G port mean?
• How to request additional bandwidth
• How to test network speed

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