Network Bandwidth Calculator — How Much Bandwidth Do You Need?
Use our free network bandwidth calculator to calculate exactly how much internet or WAN bandwidth your organisation needs based on the number of users, per-user consumption and contention ratio. Get accurate bandwidth recommendations for office networks, school networks, data centres and cloud environments — and stop overpaying for bandwidth you don't need, or underpaying and suffering poor performance.
What is a Contention Ratio?
A contention ratio describes how many users share a given amount of bandwidth. A 1:1 ratio means every user gets their full allocated bandwidth simultaneously — this is a dedicated leased line. A 1:20 ratio (typical residential broadband) means 20 users share the capacity. In practice, not all users are active simultaneously, so contention ratios are used to provision cost-effective shared infrastructure without guaranteeing simultaneous full access.
- 1:1 — Leased line, SLA-backed — guaranteed bandwidth at all times
- 1:5 — Recommended for business-critical office networks
- 1:10 — Acceptable for general office use with mixed traffic
- 1:20 to 1:50 — Typical consumer broadband — not suitable for SLA-backed services
How Much Bandwidth Does Each Application Need?
- Web browsing / email: 1–5 Mbps per user
- Video conferencing (Teams, Zoom): 3–8 Mbps per user (1080p)
- VoIP calls: 0.1 Mbps per concurrent call
- 4K video streaming: 25 Mbps per stream
- Cloud backup (background): 10–50 Mbps depending on data volume
- Remote desktop (RDP/VPN): 2–10 Mbps per user
Bandwidth Planning Best Practice
Always add a 30–40% headroom to your calculated requirement to account for traffic spikes, software updates, cloud syncing and future growth. A network running at 80%+ utilisation will experience congestion and packet loss. For mission-critical environments, consider QoS (Quality of Service) policies to prioritise VoIP and video over bulk data transfers.