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12V DC / 24V AC Max Cable Distance Voltage Drop Chart

12V DC / 24V AC Cable Distance Voltage Drop

CCTV cameras typically use 12V DC or 24VAC power supplies. Some security cameras are dual voltage which means that they can be powered by either 12V DC or 24V AC. AC and DC low voltage power supplies have limitations as to how far cable can be run before the voltage drops too low for your device to use. The maximum length that cable can be run for low voltage power varies based on these factors.

  1. Does your camera require 12 volt DC or 24 volt AC power?
  2. How much power does the device require? CCTV cameras usually have a maximum power required that is documented in the camera's specification. This is normally specified in amps / milli-amps (mA). For example: DC 500mA, DC 1A. (1 amp = 1000 mA)
  3. What size cable are you using? For example: 18 gauge, 16 gauge, 22 gauge, etc. Note: cable size is specified in AWG which stands for "American Wire Gauge".

Power to 24VAC Cameras Can be Run Further than 12V DC Cameras

If you need to run cable from your power supply to your security camera farther, you should consider using 24VAC, instead of 12V DC. Dual voltage cameras are the solution.

Low Voltage Power Drop Charts

Note: for both AC and DC low voltage, generally the maximum acceptable voltage drop is 10%. The below charts assume this.

12V DC Power Drop / Max Cable Distance Chart

The below DC voltage drop cable distance chart works as follows. The left column notes the amount of power that the device you are powering requires (red text). The "mA" after the number stands for milli-amps. For example, say you are using a CCTV camera that requires max 300mA. Using 18 gauge power cable, you can run your cable up to 289 feet.

24 AWG 22 AWG 20 AWG 18 AWG 16 AWG 14 AWG 12 AWG
DC 100mA 216 feet 342 feet 594 feet 867 feet 1,379 feet 2,197 feet 3,508 feet
DC 200mA 108 feet 171 feet 297 feet 433 feet 689 feet 1,098 feet 1,755 feet
DC 300mA 72 feet 113 feet 198 feet 289 feet 459 feet 732 feet 1,169 feet
DC 400mA 54 feet 85 feet 148 feet 216 feet 344 feet 549 feet 877 feet
DC 500mA 43 feet 68 feet 119 feet 173 feet 275 feet 439 feet 701 feet
DC 750mA 28 feet 45 feet 79 feet 115 feet 183 feet 293 feet 467 feet
DC 1000mA 21 feet 34 feet 59 feet 86 feet 137 feet 219 feet 350 feet

24V AC Power Drop / Max Cable Distance Chart

The AC voltage drop cable distance chart works the same way as the DC one. However, most 24VAC power supplies are measured in voltage amps ("VA"), or watts. Voltage amps / watts can be converted to milli-amps. You can use this voltage to watts conversion tool if the value you need is not in the below chart. We have provided the conversion for you below the VA value in the column on the left. For example, 10VA is the same as 417mA.

Using the below chart, you can see that if you are using a AC powered or dual voltage security camera that requires up to 417mA of power, you run 18 gauge power cable up to 451 feet.

24 AWG 22 AWG 20 AWG 18 AWG 16 AWG 14 AWG 12 AWG
10 VA
103 feet 283 feet 286 feet 451 feet 716 feet 1,142 feet 1,811 feet
20 VA
52 feet 141 feet 142 feet 225 feet 358 feet 571 feet 905 feet
30 VA
34 feet 94 feet 95 feet 150 feet 238 feet 380 feet 603 feet
40 VA
26 feet 70 feet 71 feet 112 feet 179 feet 285 feet 452 feet
50 VA
20 feet 56 feet 57 feet 90 feet 143 feet 228 feet 362 feet

Installer Tools & Reference Pages

Here are some additional reference pages and online tools that installers find useful

  • CAT-5 Wiring Diagram - TIA-568B standard Ethernet and crossover cable wiring diagrams.
  • Open Port Checker - this online tools tests port forwarding rules on network routers.
  • Voltage Drop Calculator - this voltage drop calculator tool is used by low voltage installers to calculate AC or DC voltage drops in amps over varying cable distances.
  • Volts to Watts Converter - this online calculator / conversion tool can convert watts to amps, volts to watts, and volts to amps.

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Mike Haldas

This article was written by , co-founder and managing partner of CCTV Camera Pros. If you found it useful, please share it. If you have any questions, please contact Mike at