Work out a practical cable size with clearer guidance than a typical one-line calculator. Compare nearby sizes, review headroom, estimate voltage drop, explore max run distance and sense-check an existing cable size in one place.
This calculator is designed to help users understand why a size looks suitable, where smaller sizes begin to fail, and where stepping up may add useful headroom.
It is a practical planning and estimating tool with straightforward outputs, cleaner layout and a more open explanation of the result.
Start with the mode that suits what you actually need on site.
| Size | Capacity | Drop % | Cost | Verdict |
|---|
This helps with estimating, pricing and early decisions before any final design is confirmed.
How far the chosen size can go at the selected load and voltage drop limit.
What the highlighted size can roughly handle over the chosen run.
A simple guide to how stepping up a size may affect material spend.
Straightforward guidance based on the current result.
These are broad practical examples only. Final suitability depends on the actual design and installation details.
Often seen on lighter circuits such as lighting, depending on the design and route.
Common for socket-related applications and general radials where the design allows.
Useful when load or distance starts to make smaller sizes less comfortable.
Frequently associated with heavier circuits, showers, cookers and some sub-main style runs.
Often considered where stronger headroom is needed or longer runs matter more.
A step up for more demanding applications, higher currents and greater distances.
A popular choice for buried and external runs to garages, sheds and outbuildings.
Useful where flexibility is required, though exact ratings depend on the product and route.
This is designed to show the thinking more openly instead of hiding it behind a black box output.
If you enter amps, that is used directly. If you enter kW, the calculator converts it using phase, voltage and power factor.
Installation method, temperature, grouping and insulation all affect the practical carrying ability.
A cable can look fine on current alone but still be a poor choice once the run gets longer.
Showing neighbouring options helps users see whether the selected size is just passing or comfortably passing.
A rough material comparison helps users weigh up headroom against spend.
Sometimes the real question is what an existing cable can reasonably handle, not what size to buy.
For planning, early estimates and comparing options, this gives a fuller picture than a simple one-number cable calculator. When the final installation matters, always verify the exact design, route, cable data and protection properly.
These answers are there to help users understand the result rather than just accepting it without context.
