Voltage is the input pressure in an electric circuit which pushes the electric current (charges i.e positive and negative charges) through a conducting circuit.
Usually, electric wires are used to conduct current in an electric circuit. Different wires are manufactured with different conducting materials e.g copper silver, nickel etc. These different types of wires have different resistivity, diameter, cross-sectional area, and other electric properties.
All these properties and lengths of wire used in the electric circuits do reduce the pressure input of voltage. This decrease in voltage generated by the wire's electric properties and its length is often referred to as voltage drop. This page offers an online voltage drop calculator to estimate the drop in voltage triggered by the electric & Physical qualities of wire.
Just select & put in the required parameters and press the calculate button:
* @ 68°F or 20°C
** Results may change with real wires: different resistivity of material and number of strands in wire.
*** For wire length of 2x10ft, wire length should be 10ft.
The voltage drop V in volts (V) is equal to the wire current I in amps (A) times 2 times one way wire length L in feet (ft) times the wire resistance per 1000 feet R in ohms (Ω/kft) divided by 1000:
Vdrop (V) = Iwire (A) × Rwire(Ω)
= Iwire (A) × (2 × L(ft) × Rwire(Ω/kft) / 1000(ft/kft))
The voltage drop V in volts (V) is equal to the wire current I in amps (A) times 2 times one way wire length L in meters (m) times the wire resistance per 1000 meters R in ohms (Ω/km) divided by 1000:
Vdrop (V) = Iwire (A) × Rwire(Ω)
= Iwire (A) × (2 × L(m) × Rwire (Ω/km) / 1000(m/km))
The line to line voltage drop V in volts (V) is equal to square root of 3 times the wire current I in amps (A) times one way wire length L in feet (ft) times the wire resistance per 1000 feet R in ohms (Ω/kft) divided by 1000:
Vdrop (V) = √3 × Iwire (A) × Rwire (Ω)
= 1.732 × Iwire (A) × (L(ft) × Rwire (Ω/kft) / 1000(ft/kft))
The line to line voltage drop V in volts (V) is equal to square root of 3 times the wire current I in amps (A) times one way wire length L in meters (m) times the wire resistance per 1000 meters R in ohms (Ω/km) divided by 1000:
Vdrop (V) = √3 × Iwire (A) × Rwire (Ω)
= 1.732 × Iwire (A) × (L(m) × Rwire (Ω/km) / 1000(m/km))
The n gauge wire diameter dn in inches (in) is equal to 0.005in times 92 raised to the power of 36 minus gauge number n, divided by 39:
dn (in) = 0.005 in × 92(36-n)/39
The n gauge wire diameter dn in millimeters (mm) is equal to 0.127mm times 92 raised to the power of 36 minus gauge number n, divided by 39:
dn (mm) = 0.127 mm × 92(36-n)/39
The n gauge wire's cross sercional area An in kilo-circular mils (kcmil) is equal to 1000 times the square wire diameter d in inches (in):
An (kcmil) = 1000×dn2 = 0.025 in2 × 92(36-n)/19.5
The n gauge wire's cross sercional area An in square inches (in2) is equal to pi divided by 4 times the square wire diameter d in inches (in):
An (in2) = (π/4)×dn2 = 0.000019635 in2 × 92(36-n)/19.5
The n gauge wire's cross sercional area An in square millimeters (mm2) is equal to pi divided by 4 times the square wire diameter d in millimeters (mm):
An (mm2) = (π/4)×dn2 = 0.012668 mm2 × 92(36-n)/19.5
The n gauge wire resistance R in ohms per kilofeet (Ω/kft) is equal to 0.3048×1000000000 times the wire's resistivity ρ in ohm-meters (Ω·m) divided by 25.42 times the cross sectional area An in square inches (in2):
Rn (Ω/kft) = 0.3048 × 109 × ρ(Ω·m) / (25.42 × An (in2))
The n gauge wire resistance R in ohms per kilometer (Ω/km) is equal to 1000000000 times the wire's resistivity ρ in ohm-meters (Ω·m) divided by the cross sectional area An in square millimeters (mm2):
Rn (Ω/km) = 109 × ρ(Ω·m) / An (mm2)
| AWG # | Diameter (inch) |
Diameter (mm) |
Area (kcmil) |
Area (mm2) |
|---|---|---|---|---|
| 0000 (4/0) | 0.4600 | 11.6840 | 211.6000 | 107.2193 |
| 000 (3/0) | 0.4096 | 10.4049 | 167.8064 | 85.0288 |
| 00 (2/0) | 0.3648 | 9.2658 | 133.0765 | 67.4309 |
| 0 (1/0) | 0.3249 | 8.2515 | 105.5345 | 53.4751 |
| 1 | 0.2893 | 7.3481 | 83.6927 | 42.4077 |
| 2 | 0.2576 | 6.5437 | 66.3713 | 33.6308 |
| 3 | 0.2294 | 5.8273 | 52.6348 | 26.6705 |
| 4 | 0.2043 | 5.1894 | 41.7413 | 21.1506 |
| 5 | 0.1819 | 4.6213 | 33.1024 | 16.7732 |
| 6 | 0.1620 | 4.1154 | 26.2514 | 13.3018 |
| 7 | 0.1443 | 3.6649 | 20.8183 | 10.5488 |
| 8 | 0.1285 | 3.2636 | 16.5097 | 8.3656 |
| 9 | 0.1144 | 2.9064 | 13.0927 | 6.6342 |
| 10 | 0.1019 | 2.5882 | 10.3830 | 5.2612 |
| 11 | 0.0907 | 2.3048 | 8.2341 | 4.1723 |
| 12 | 0.0808 | 2.0525 | 6.5299 | 3.3088 |
| 13 | 0.0720 | 1.8278 | 5.1785 | 2.6240 |
| 14 | 0.0641 | 1.6277 | 4.1067 | 2.0809 |
| 15 | 0.0571 | 1.4495 | 3.2568 | 1.6502 |
| 16 | 0.0508 | 1.2908 | 2.5827 | 1.3087 |
| 17 | 0.0453 | 1.1495 | 2.0482 | 1.0378 |
| 18 | 0.0403 | 1.0237 | 1.6243 | 0.8230 |
| 19 | 0.0359 | 0.9116 | 1.2881 | 0.6527 |
| 20 | 0.0320 | 0.8118 | 1.0215 | 0.5176 |
| 21 | 0.0285 | 0.7229 | 0.8101 | 0.4105 |
| 22 | 0.0253 | 0.6438 | 0.6424 | 0.3255 |
| 23 | 0.0226 | 0.5733 | 0.5095 | 0.2582 |
| 24 | 0.0201 | 0.5106 | 0.4040 | 0.2047 |
| 25 | 0.0179 | 0.4547 | 0.3204 | 0.1624 |
| 26 | 0.0159 | 0.4049 | 0.2541 | 0.1288 |
| 27 | 0.0142 | 0.3606 | 0.2015 | 0.1021 |
| 28 | 0.0126 | 0.3211 | 0.1598 | 0.0810 |
| 29 | 0.0113 | 0.2859 | 0.1267 | 0.0642 |
| 30 | 0.0100 | 0.2546 | 0.1005 | 0.0509 |
| 31 | 0.0089 | 0.2268 | 0.0797 | 0.0404 |
| 32 | 0.0080 | 0.2019 | 0.0632 | 0.0320 |
| 33 | 0.0071 | 0.1798 | 0.0501 | 0.0254 |
| 34 | 0.0063 | 0.1601 | 0.0398 | 0.0201 |
| 35 | 0.0056 | 0.1426 | 0.0315 | 0.0160 |
| 36 | 0.0050 | 0.1270 | 0.0250 | 0.0127 |
| 37 | 0.0045 | 0.1131 | 0.0198 | 0.0100 |
| 38 | 0.0040 | 0.1007 | 0.0157 | 0.0080 |
| 39 | 0.0035 | 0.0897 | 0.0125 | 0.0063 |
| 40 | 0.0031 | 0.0799 | 0.0099 | 0.0050 |
A voltage drop in an electrical circuit typically happens when a flow goes through the link. It is connected with the obstruction or impedance to current stream with detached components in the circuits including links, contacts and connectors influencing the degree of voltage drop.