Created By : Vaibhavi Kumari

Reviewed By : Phani Ponnapalli

Last Updated : May 14, 2023


To simply determine the voltage drop or load current of a conductor, use our user-friendly Voltage-Drop Calculator. Simply enter the load current, conductor material, and beginning voltage into the calculator's input boxes and press the calculate button to get the result in a short amount of time.

What is Voltage Drop?

The voltage drop is the decrease in voltage. It happens when an electric current passes through the circuit's passive parts. Conductor material type, conductor length, a cross-sectional area of the wire, and load current are all factors that affect the voltage drop of a conductor.

The voltage drop formula is as follows For DC or 1-phase AC, V = 2 x I x L x R / A / n

For 3-phase AC, V = √3 x I x L x R / A / n

  • Where, V = voltage drop
  • I = load current
  • L = length of the wire
  • R = resistivity of the wire
  • A = cross-sectional area of the wire
  • n = number of conductors that are connected in parallel

Typical AWG Wire Sizes

AWG means American Wire Gauge, it is used to measure the diameters of round, non-ferrous, and electrically conducting wire in North America. The following is a list of common AWG wires and their sizes

AWG Diameter (inch) Turns of Wire (per inch) Area (kcmil) Copper resistance (Ω/km)
0000 (4/0) 0.4600 2.17 212 0.1608
000 (3/0) 0.4096 2.44 168 0.2028
00 (2/0) 0.3648 2.74 133 0.2557
0(1/0) 0.3249 3.08 106 0.3224
1 0.2893 3.46 83.7 0.4066
2 0.2576 3.88 66.4 0.5127
3 0.2297 4.36 52.6 0.6465
4 0.2043 4.89 41.7 0.8152
5 0.1819 5.50 33.1 1.028
6 0.1620 6.17 26.3 1.296
7 0.1443 6.93 20.8 1.634
8 0.1285 7.78 16.5 2.061
9 0.1144 8.74 13.1 2.599
10 0.1019 9.81 10.4 3.277
11 0.0907 11.0 8.23 4.132
12 0.0808 12.4 6.53 5.211
13 0.0720 13.9 5.18 6.571
14 0.0641 15.6 4.11 8.286
15 0.0571 17.5 3.26 10.45
16 0.0508 19.7 2.58 13.17
17 0.0453 22.1 2.05 16.61
18 0.0403 24.8 1.62 20.95
19 0.0359 27.9 1.29 26.42
20 0.0320 31.3 1.02 33.31
21 0.0285 35.1 0.810 42
22 0.0253 39.5 0.642 52.96
23 0.0226 44.3 0.509 66.79
24 0.0201 49.7 0.404 84.22
25 0.0179 55.9 0.320 106.2
26 0.0159 62.7 0.254 133.9
27 0.0142 70.4 0.202 168.9
28 0.0126 79.1 0.160 212.9
29 0.0113 88.8 0.127 268.5
30 0.0100 99.7 0.101 338.6
31 0.00893 112 0.0797 426.9
32 0.00795 126 0.0632 538.3
33 0.00708 141 0.0501 678.8
34 0.00630 159 0.0398 856
35 0.00561 178 0.0315 1079
36 0.00500 200 0.0250 1361
37 0.00445 225 0.0198 1716
38 0.00397 252 0.0157 2164
39 0.00353 283 0.0125 2729
40 0.00314 318 0.00989 3441

How do you Calculate Voltage Drop?

The steps for calculating the voltage drop are as follows. By following these guidelines, you'll be able to get more done in less time.

  • Step 1: Check the length of the conductor, the current drawn by the load, the initial voltage, and the resistance of the wire.
  • Step 2: Multiply the length and resistance to double the load current.
  • Step 3:To get the voltage drop, divide the product by the wire's cross-sectional area.

How to find Voltage Drop using Calculator?

The following sections will show you how to simply calculate the voltage drop.

  • Step 1: Select the initial voltage. Choose whether your system runs on 12 V or 24 V.
  • Step 2: Choose between AC and DC. Select the voltage type for your system. The most common choices will be 12 Vdc and 24 Vac.
  • Step 3: Enter the amps of your camera's current. 1 amp = 1000 milliamperes. Enter 0.3 in this field if your camera draws 300 mA.
  • Step 4: In feet, enter the length of your cable.
  • Step 5: Enter the length of your cable here. The standard for CCTV is 18 awg.
  • Step 6: Select the 'Calculate' button from the drop-down menu. To clear the results and start over, click 'Cancel.'

For more concepts check out physicscalculatorpro.com to get quick answers by using this free tool.

Voltage Drop Example Calculation

Question 1: An 8 A current runs through a circuit with a resistance of 15 Ω and a wire length of 7 metres. Find the voltage drop for a wire with a cross-sectional area of 30 sq m.

Solution:

Given that Load current I = 8 A

Resistance R = 15 Ω

Cross-sectional Area A = 30 sq m

Wire length L = 7 m

Voltage drop V = 2 x I x L x R / A

V = 2 x 8 x 7 x 15 / 30

= 56 V

Hence, the voltage drop is 56 V.

FAQs on Voltage Drop

1. In a series circuit, how do you calculate voltage drop?

To calculate the voltage drop across a component E, you'll need to know the component's resistance and the current flowing through it. E=IR is Ohm's Law, which tells us to multiply I by R. The voltage across the component, also called voltage drop. It is denoted by E.


2. What is the method of calculating the voltage drop?

Calculate the product of load current, wire length, and wire resistance to determine the voltage drop in a wire. Divide the result by the wire's cross-sectional area before dividing it by the number of conductors.


3. What factors have an impact on the amount of the voltage drop?

The voltage drop in a wire occurs when the current has to pass along it. Wire material type, wire size, wire length, and load current are all factors that influence voltage drop.


4. How do you measure voltage in a circuit?

You don't have to put the metre into the circuit to measure the voltage on an electrical circuit. All you have to do now is touch the multimeter's leads to any two spots in the circuit. The voltage between those two places is displayed on the multimeter when you do so.