12V Camera Voltage Drop Calculator

For 12 V DC / analog cameras on solid copper or aluminum. Enter the camera load, the one-way cable length, and the wire gauge to see the voltage that actually reaches the camera, a pass/caution/fail verdict, the wire size to use, and how far you can run it. Advanced options add aluminum conductors, a custom drop target, and shared-camera runs. Running PoE instead? Use the PoE Voltage Drop Calculator. New to 12V power loss? Read the full 12V voltage-drop guide.

Supply voltage 12 V DC

Maximum / night (IR-on) current (amps)

Use the camera’s max draw with IR on, from the label or spec sheet. Switching Amps/Watts converts the value (12 V). Amps is the preferred input.

One-way cable length (ft) — camera to power

Wire gauge (AWG, copper)

Camera minimum voltage (V) — required

Required — there is no default. The pass/fail is judged against this, so the calculator shows no verdict until you enter it. Find it on the camera’s spec sheet. If you truly can’t, 10.8 V is a conservative floor for many 12V cameras — but verify, since many need more.

Advanced options — conductor, drop target, shared cameras

Conductor material

Allowable voltage drop (target %)

Your pass target. Stay at 5% when you can; 10% is the absolute ceiling, not a goal. The verdict still fails any run above 10% drop or below your camera’s minimum voltage, whatever target you pick.

Cameras sharing this one conductor pair

Simplified model: identical cameras, each at the load above, sharing one pair (their current adds on the shared run). Not a full branched-circuit model — dedicated home-run pairs (each camera its own pair back to the supply) are preferred; check mixed loads leg by leg.

Estimates for planning only, based on solid copper or aluminum (per your selection) at ~20–25 °C. CCA (copper-clad aluminum), stranded wire, temperature, and IR/heater/PTZ loads change real results. Use listed power supplies and wire. The pass/fail verdict is judged against the camera minimum voltage you enter — a required input with no default. Enter your camera’s real minimum from its spec sheet; without it the calculator shows no verdict. For line-voltage work, consult a licensed electrician.

Source: Guard Source HQ — guardsourcehq.com/12v-voltage-drop-calculator. Free to cite with attribution and a link back.