Electrical Cable Size Calculator & Cable Size Chart Amps

Electrical cables are the lifelines of any electrical system, transmitting power from one point to another. Keeping in mind the very crucial job they conduct, choosing the right cable size in electrical installations is of utmost importance to ensure the safety, efficiency, and optimal performance. The longevity of your electrical devices and appliances also depends on the kind and quality of cable you use to connect them to the electrical supply. Hence it is important to choose the type of wiring and the size carefully. 

Let us look into the types of cables along with their cable sizing chart and discuss the significance of correct cable sizing.

Types of Electrical Cable Size

Electrical cables are available in different sizes depending on the intended application or current passing through. The actual diameter of a cable is expressed in millimeters to give information on the cross sectional area which in turn defines current rating of a specific cable. Standard cables for current circuits range between 1.5mm² for lighting circuits and 2.5mm² up for power sockets.

How to Choose the Right Electrical Cable for Your Needs?

The different kinds of wiring are as follows:

1. 1. Cables

   Cables are generally used for permanent wiring, acting as conduits for distributing electrical power throughout a building’s infrastructure or through the power grids. Typically concealed from plain view, cables are hidden behind walls, ceilings, and floors ensuring a seamless and organized electrical system.

   A standard cable will have two essential components –

   • The core, and 

   • The PVC sheathing
     

   Choosing the appropriate core size and proper sheathing is essential for matching the cable to specific electrical applications.

   Two-core-and-earth-cables, also known as twin-core-and-earth-cables, feature three core types, each identifiable by the color of its sheathing, which is:

   • The live core is insulated with a brown sheath

   • The neutral core is insulated with a blue sheath, and 

   • The earth's core is devoid of any sheathing

   The twin-core-and-earth electrical cable size chart amps are as given below:

   Size	Amps	Energy	Utility
   1.0 mm2	14A	3.25kW at 240V	lighting applications
   1.5 mm2	18A	4.25kW at 240V	lighting applications
   2.5 mm2	24A	5.75kWat 240V	power circuits
   4.0 mm2	32A	7.75kW at 240V	power circuits and shower applications
   6.0 mm2	40A	12.9kW at 240V	shower and cooker applications
   10 mm2	53A	12.9kW at 240V	cooker applications

   Three-core-and-earth cables are commonly used in scenarios where additional connections are required. Similar to twin-core-and-earth cables, the cable sizes here also correspond with a current and wattage. However, these cables are only used for two-way switching of lights.

   1.0 mm2 — 12A in current, 2.75kW at 240V used for lighting two-way switches.

2. 2. Flex

   Flex, also known as flexible cable, usually serves as a stranded electrical wire to connect appliances and pendant lights to the main wiring network. 

   Similar to cables, flexes also have three color-coded cores, which are as follows:

   • The brown core provides live insulation, carrying the active current to power the connected appliance or light fixture

   • The blue core serves as neutral insulation and forms a return path for the current thereby ensuring a complete and safe circuit

   • The earth core which is green or yellow and offers a low-resistance path in case of abnormal current flow, directing current to the ground and preventing potential damage.
     

   Properly matching the flex size to the appliance’s wattage ensures that the cable can handle the required current without overheating or posing any safety risks. 

   Given below are the electrical cable size calculator chart for flex sizes and the corresponding rating of suitable appliances.

   Size	Corresponding Appliance Rating
   0.5 mm2	700W
   0.75 mm2	1400W
   1 mm2	2300W
   1.25 mm2 or 1.5 mm2	3000W

3. 3. Armoured Cables 

   Armored cables are specifically designed for the transmission of data or power in challenging environments such as underground or overload installations. Unlike the two previously mentioned cable types, armored cables incorporate an additional layer of protection in the form of a metal sheet, hence the name ‘armored’.

   Given below are the rating electrical cable size chart amps - standard core sizes of three-stranded armored cables, along with their respective capacities and wattage ratings.

   Size	Amps	Energy
   1.5 mm2	18A	4.25kW at 240V
   2.5 mm2	24A	5.75kWat 240V
   6.0 mm2	41A	9.9kW at 240V
   10 mm2	56A	12.5kW at 240V
   16.0 mm2	85A	20.5kW at 240V
   25.0 mm2	104A	25.25kW at 240V

   
   

   However, it is essential to note that some manufacturers may include certain other specifications for their armored cables, which are often printed on the insulation itself.

   Read Also: Type of Electric Cables & Conductors with Application

How to Determine the Appropriate Cable Size?

You must consider the following factors to determine the appropriate cable size:

• Refer to the package label first. You can find a detailed label on the package. Check it for brand, model and size.
• You can also find the cable’s information printed on its insulated layer.
• Visual inspection is also essential when determining the right cable size. However, you need extensive experience for this.
• You can also use a vernier caliper or a micrometer to measure the cable’s diameter.

Importance of Correct Cable Sizing

Using the correct cable size in electrical installations is crucial for several reasons, some of which are as follows:

• Properly sized cables reduce the risk of electrical accidents due to overheating of wires and ensure safety.

• Correctly sized cables minimize voltage drops, ensuring the electrical equipment receives the required voltage for optimal performance.

• Adhering to cable sizing standards and regulations is essential for compliance with electrical codes and safety guidelines.

Remember to consult a qualified electrician or electrical engineer for complex installations or if you are unsure about cable sizing for critical applications. You may also speak with your chosen manufacturer to check the parity between cable sizes and applications.

Conclusion

Choosing the right size of the electric cable plays an important role in providing safety, high efficiency and lasting operation during electrical connection. It is apparent that the size requirements vary depending on wire load capacity in watts, current rating and environmental conditions for the particular line. It becomes easier when you use a wire selection chart or employ the services of cable size calculators. It will always be wise to select the right cable in order to overcome risks of overheating, electrical breakdowns and inefficient energy transmission. Proper cabling means your electrical system would run well and meet your requirements efficiently.

Schneider Electric is one of the most reliable brands in the market for all kinds of highest-quality electrical equipment, devices, as well as wiring. The eShop is a one-stop destination for all kinds of electrical devices and appliances such as cables, switches, circuit-breakers, home automation, power suppliers, and so on in India. The eShop offers a convenient shopping experience along with affordable prices and lucrative warranties on its products. Visit the Schneider Electric eShop’s website to know all about the wide variety of electrical products they offer and the services they provide. 

If you have any queries about the cable sizes or would like to speak with the electrical experts for advice, feel free to contact the eShop today!

FAQs About

Q1. How to calculate amps and cable size?

Ans: To calculate the required cable size, first, determine the current in amps (I) using the formula: I=P/V, where P = power, measured in watts and V = voltage in volts. Refer to wire size chart in order to get the correct cable size corresponding to the current rating.

Q2. How many amps is 1.5 mm cable?

Ans: A 1.5mm² conductor has a carrying capacity of approximately 16-20A, based on its insulation type and environmental conditions under which it was used. This can be useful in lighting circuits or other low power circuits where it is needed to ramp up the current, or to dissipate noise.

Q3. How to check cable size?

Ans: To ensure that cable size is correct, it should be indicated by the outer sheath of the conductor, which presents a cross sectional area in millimeters square. You can also use a measuring tape to get the diameter of the conductor then use the cable size chart.

Q4. What is a 10mm cable used for?

Ans: A 10mm² cable is used where high current is to be carried to or from a circuit such as for electric cookers, showers or industrial machines etc.

Q5. What is sq mm in cable?

Ans: The term ‘’sq mm” means square millimeters that denote the area of cross section of the conductor in a cable. The other means it to denote the electric cable size and since it directly determines the amount of current the cable can handle at a given time. This then gives capacity to larger cross-sectional areas for carrying larger current.