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PoE distance and budget calculator
Check switch budget, per-port class limits, runs past 100 m, and voltage drop. Voltage at the device solves P = V·I − I²R.
Plan
364.8 W allocated of 370 W (98.6%). 5.2 W left. PD draw 308.4 W.
| Device | Standard | PD max W | Alloc W | Run | |
|---|---|---|---|---|---|
| Cam 1–12 × 12 | 802.3af Type 1 | 12.95 | 15.4 | 60 m | OK |
| Cam 13–15 × 3 | 802.3at Type 2 | 25.5 | 30.0 | 85 m | OK |
| Cam 16 × 1 | 802.3at Type 2 | 25.5 | 30.0 | 120 m | Over 100 m |
| AP 1 × 1 | 802.3bt Type 3 | 51.0 | 60.0 | 40 m | OK |
Cam 16 at 120 m is past the 100 m channel limit.
Cam 16 voltage drop
25.5 W at the device, 50 V minimum at the switch, 120 m.
Loop resistance 7.9 Ω. Current 0.56 A. Voltage drop 4.4 V, so 45.6 V at the device. Cable loss 2.5 W.
IEEE 802.3 PoE reference
| Standard | Type | PSE out | PD max | Min V | Max loop Ω | Pairs |
|---|---|---|---|---|---|---|
| 802.3af | 1 | 15.4 W | 12.95 W | 44 V | 20.0 | 2 |
| 802.3at | 2 | 30.0 W | 25.5 W | 50 V | 12.5 | 2 |
| 802.3bt | 3 | 60.0 W | 51.0 W | 50 V | 6.25 | 4 |
| 802.3bt | 4 | 90.0 W | 71.3 W | 52 V | 6.25 | 4 |
100 m channel. Values from IEEE 802.3 tables via the Ethernet Alliance overview. 23 AWG is 0.066 Ω/m and 24 AWG is 0.084 Ω/m. Four-pair 802.3bt uses half the loop resistance.
Cameras to try
Open a camera to see its manufacturer specs and run this tool with them filled in.
- Axis M5526-E4 MP
- Axis P3747-PLVE4x 5 MP
- Axis P3285-LVE Kit2 MP
- Axis P3735-PLE4x 2 MP
- Hanwha Vision PND-A6081RF2 MP
- Hanwha Vision PND-A6081RV2 MP
- Hanwha Vision PND-A7082RV4 MP
- Hanwha Vision PND-A9081RF8 MP
Brands: Axis (4 cameras) · Hanwha Vision (348 cameras)