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The Fastest Way to Find the Right Cable for Your Project
Looking for the correct cable size? Save time and ensure safety with Batt Cables’ easy-to-use Cable Calculator – designed by experts for professionals. From industrial installations to domestic wiring, our calculator helps you choose the right cable for current capacity, voltage drop, and application needs.
Why Use Our Cable Calculator?
Precision matters. Choosing the wrong cable size can result in overheating, energy loss, or compliance issues. Our tool eliminates guesswork by giving you instant, reliable calculations based on:
Voltage (V)
Current (A)
Cable Length (m)
Installation Method
Conductor Type
Single-phase or Three-phase
Whether you’re specifying for armoured cables, flexible cords, low voltage wiring, or underground systems, our calculator has you covered.
Trusted by Engineers, Electricians, and Contractors
As a leading UK supplier of power, control, and data cables for over 70 years, Batt Cables delivers technical accuracy and unmatched product support. We supply everything from armoured power cables to fire performance cables – and our calculator helps you select the right one, the first time.
How it Works
Enter your project specs – voltage, current, and length.
Select the environment – installation method, cable type, etc.
Get your results – see recommended cable sizes, volt drop %, and load capacity.
Need Help After Calculating?
Browse our full product range
Contact our technical team for custom advice
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Why Choosing the Correct Cable Size Matters
Selecting the proper cable size is crucial for safety, efficiency, and long-term performance. An undersized cable can overheat, suffer excessive voltage drop, waste energy, and violate compliance or electrical standards. A correctly sized cable reduces fire risk, improves system lifespan, ensures electrical loads are handled safely, and helps you avoid costly maintenance or replacement. Using our cable calculator helps you determine correct conductor size for fixed wiring, motor applications, and general power distribution.
Key Factors to Consider When Sizing Cables
Beyond the basic inputs (voltage, current, cable length, installation method), there are additional factors that affect the correct cable selection:
Voltage Drop Limitation: In long runs, voltage drop can reduce voltage available at the load. Always check that drop stays within acceptable limits.
Installation Environment: Cables in conduit, trunking, enclosed walls, or clipped direct to wall will have different heat dissipation. Whether the cable is armoured or not affects this.
Ambient Temperature: Higher ambient temperature reduces current capacity—account for any heat sources or ambient conditions.
Load Type: Motor and inductive loads have different starting currents (inrush); using a multiplier (e.g., 4× rated current) may be necessary for motor circuits.
Conductor Material and Insulation Type: Copper vs aluminium conductors behave differently; PVC vs LSZH or XLPE insulation/sheath alters allowable temperature and durability.
Common Mistakes to Avoid
When estimating cable size, people often make mistakes such as:
Using straight-line length and ignoring additional length from bends or routing.
Forgetting to include allowance for voltage drop, especially in long cable runs.
Assuming insulation or sheath type doesn’t matter for temperature rating.
Underestimating starting current for motors or inductive loads.
Choosing cheaper cables without proper specifications or certification.
Glossary of Terms
| Term | Definition |
|---|---|
| Conductor Size (mm²) | The cross-sectional area of the cable conductor; larger sizes carry more current. |
| Voltage Drop | The loss of voltage in the cable due to its resistance; increases with length and load. |
| Armoured Cable | Cable with mechanical protection (steel wire or tape) suitable for underground or exposed runs. |
| LSZH | Low Smoke Zero Halogen — a cable sheath that emits low smoke and no halogen when exposed to fire. |
| PVC Insulated | Standard insulation material, suitable for many fixed wiring applications. |
| Installation Method | How and where the cable is installed (in conduit, clipped, enclosed etc.), which affects heat dissipation. |
Tips for Using the Cable Calculator Effectively
Always round up to the next cable size if your calculated size is between standard sizes.
Review the installation path (number of bends, distance) to ensure the actual cable run is not much longer than estimated.
Spectrum of cable types: armoured, steel wire armoured (SWA), aluminium wire armoured (AWA), LSZH etc., can influence cost and installation method.
Keep your installation compliant with local electrical regulations and wiring codes. If in doubt, consult a qualified electrician.
