How many of each activity happen at the same time on your busiest evening? That peak moment is what your speed has to survive.
| Simultaneous activity | Count | Each | Subtotal |
|---|
How to use the home internet speed planner
The method
Each simultaneous activity is given its typical demand (4K stream 25 Mbps, HD stream 5, HD video call 3, gaming 5, home-working 10). Add up the peak, then add 30% headroom for protocol overhead, Wi-Fi losses and growth — and round up to the nearest commonly sold tier.
Labelled honestly
This is a planning estimate. Real demand varies by service and settings, and a speed test at your busiest hour beats any calculator — including this one.
Example
One 4K stream + one HD stream at the same time = 25 + 5 = 30 Mbps peak; with 30% headroom = 39 Mbps — so a 50 Mbps plan is the sensible buy, and a 36 Mbps plan would buffer on the busiest evenings.
Frequently asked questions
Why plan for simultaneous use instead of total devices?
Because speed is shared at each moment, not across the day. Ten devices that take turns need far less than four that all stream at 7pm. Count the busiest moment, not the device list.
Is faster always better?
No. Beyond your peak need plus headroom, extra speed mostly benefits big downloads (they finish sooner) rather than streaming or calls. A household peaking at 40 Mbps gains little from 900 Mbps — except shorter game downloads.
What about upload speed?
Video calls, working from home and cloud backups live on upload. If your household has home workers, favour plans with stronger upload (full-fibre symmetric services where available) over a bigger download headline.
More free tools
Download & Upload Time Calculator
How long will that file take at your speed? Enter the file size and connection speed — or work backwards from the time you have.
Data Usage Estimator
Add up streaming, video calls, gaming and browsing to estimate your real monthly data usage in GB.
Speed Unit Converter
Convert Mbps, Gbps, MB/s and more — and finally see the difference between bits and bytes, in plain English.
IPv4 Subnet Calculator
Network address, broadcast, netmask, wildcard, host range and usable hosts from any IP and CIDR — done properly, including /31 and /32.
SLA Uptime Calculator
What does 99.9% uptime actually allow? See permitted downtime per day, week, month and year for any SLA percentage.
Data Plan Cost Calculator
Compare two mobile or broadband plans fairly: cost per GB, overage at your real usage, and the true monthly total.