Bandwidth Calculator
Calculate the bandwidth a household or office needs from its usage and devices.
Last updated · View algorithm, constants and default inputs (JSON)
About this calculator
Streaming dominates household bandwidth: a 4K stream needs about 25 Mbps on its own, and HD about 5. Adding simultaneous users rather than averaging them is what matters, because the peaks are what cause buffering.
Worked example
calculated with the default values below
People using the connection 4 · Simultaneous 4K streams 1 · Simultaneous HD streams 2 · Gaming or video calls 2 · Large downloads running 1 · Smart home devices 15 · People working from home 1 Peak demand 123.5 Mbps · Recommended plan speed 175 Mbps · Per person at peak 30.9 Mbps · Recommended upload speed 25 Mbps · Note Buffering is usually a peak-hour or Wi-Fi problem rather than a raw speed problem — check router placement before upgrading the plan
General background references
Disclaimer
These calculators give general date results. Public holidays, working-day conventions and time-zone rules are set locally and change, so confirm against the official calendar for anything legally or contractually binding.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
P = 2n + Σ aⱼ xⱼ; R = ⌈1.4 P ÷ 25⌉ × 25
- n
- People
- xⱼ
- Count of each activity
- aⱼ
- Activity weights: 25/5/4/50/0.5/15
- P
- Peak demand, Mbps
- R
- Recommended speed, Mbps
Weights: 4K 25, HD 5, gaming 4, downloads 50, smart devices 0.5, work-from-home 15; R rounds up to 25-Mbps tiers with 40% headroom.
Frequently asked questions
Why does one large download count as much as ten HD streams?
The peak-demand model adds 50 Mbps per simultaneous download and 5 Mbps per HD stream, so one download contributes the same as ten streams. It multiplies total peak demand by 1.4, then rounds the suggested plan up to the next 25 Mbps increment. The upload estimate uses a separate formula based on work-from-home sessions, gaming and 4K streams.