Low-Voltage Drop Calculator
Calculate voltage drop for AV, security, automation, and PoE wiring with visual gradient and gauge recommendations.
AWG (lower = thicker wire). ★ = recommended for ≤3% drop.
Voltage at End of Run
9.4V
Excessive drop — 78.3% of source retained
Voltage Drop
2.6V
Over 200 ft round-trip
Drop Percentage
21.67%
Exceeds 5% — not recommended
Power Loss in Wire
5.2W
21.7% of total power wasted as heat
Pro Tip
At 21.67% drop, devices may malfunction. Try 10 AWG, a shorter run, or higher source voltage.
Voltage Along the Wire Run
All Gauges Compared — 12V, 2A, 100 ft, copper
| Gauge | V Drop | % Drop | V at End | Power Loss | Status |
|---|---|---|---|---|---|
| 10 AWGRecommended | 0.41 V | 3.42% | 11.59 V | 0.82 W | |
| 12 AWG | 0.65 V | 5.42% | 11.35 V | 1.3 W | |
| 14 AWG | 1.03 V | 8.58% | 10.97 V | 2.06 W | |
| 16 AWG | 1.64 V | 13.67% | 10.36 V | 3.28 W | |
| 18 AWGSelected | 2.6 V | 21.67% | 9.4 V | 5.2 W | |
| 20 AWG | 4.14 V | 34.5% | 7.86 V | 8.28 W | |
| 22 AWG | 6.58 V | 54.83% | 5.42 V | 13.16 W |
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Find an InstallerUnderstanding Voltage Drop in AV & Low-Voltage Installations
Voltage drop is the reduction in voltage as current travels through wire. In low-voltage systems — 12V, 24V, and 48V circuits common in AV, security, and automation — even small drops cause real problems. A 12V camera may fail at 10.5V. A powered speaker on a long 24V run may distort. Door strikes can fail to engage.
The PoE Calculator mode handles Power over Ethernet budgets for 802.3af, at, and bt standards. It shows how much power actually reaches your device after wire losses, critical for IP cameras, access points, and building automation on long Cat6 runs.
Keep total drop under 5%, though many professionals target 3% or less for critical systems. The visual gradient shows exactly how voltage degrades along your wire run. Pair with our Speaker Wire Gauge Calculator and Conduit Fill Calculator.
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