PoE Budget Calculator
Add up the PoE draw of cameras, APs and IP phones to get a switch budget with 20% headroom. PTZs that need 802.3bt get flagged.
PoE devices
Use the datasheet "max power consumption" (IR / heater on).
Results
Required PoE budget (at switch)
579W
Draw at devices
270W
PoE ports
30
Recommended switch budget (+20%)
≥ 695 W
→ Choose a PoE switch with a 740 W PoE budget or more
Ports by standard
- 802.3af ≤ 12.95 W22
- 802.3at (PoE+) ≤ 25.5 W8
How we calculate
IEEE 802.3 PoE classes (PD = at device, PSE = at switch port):
| Standard | Class | PD max | PSE port |
|---|---|---|---|
| 802.3af | 0–3 | 12.95 W | 15.4 W |
| 802.3at (PoE+) | 4 | 25.5 W | 30 W |
| 802.3bt Type 3 (Class 5) | 5 | 40 W | 45 W |
| 802.3bt Type 3 (Class 6) | 6 | 51 W | 60 W |
| 802.3bt Type 4 (Class 7) | 7 | 62 W | 75 W |
| 802.3bt Type 4 (Class 8) | 8 | 71.3 W | 90 W |
1. Each device is classed from its maximum draw. Above 25.5 W requires 802.3bt.
2. By class: budget = Σ class PSE max × qty. Actual: budget = Σ watts × (class PSE ÷ class PD) × qty: includes worst-case 100 m cable loss.
3. Recommended switch = budget × 1.2, rounded up to a common switch PoE budget.
4. Some switches derate PoE at high ambient temperature. Check the datasheet for cabinets without air-conditioning.
These results are estimates to help with planning and budgeting. Our engineers will verify everything on site before final design and equipment proposal.
The same rules of thumb our engineers use for a first design. Good enough for budgeting; the final numbers come from a site survey.
Tools
Solar System Sizing Calculator
Enter kWh from your bill or a device list; get panel size (kWp), inverter, LiFePO4 battery and roof area for on-grid, hybrid and off-grid systems.
Open calculator
CCTV Storage Calculator
Enter cameras, resolution, codec and retention days; get total TB, per-camera bitrate and a drive/RAID layout for the NVR.
Open calculator
UPS Sizing & Runtime Calculator
Add up servers, switches and NAS to get a UPS rating (VA/W) with 25% headroom and the battery energy to ride through an outage.
Open calculator
Internet Bandwidth Calculator
Before you renew with your ISP: size download and upload from users, cloud apps, video calls and remote CCTV viewing.
Open calculator
Wi-Fi Access Point Estimator
Counts access points two ways, by floor area and by people online at once, for Wi-Fi 6, 6E and 7. The higher number wins.
Open calculatorSend us a floor plan or a few photos of the site
We’ll come back with a few questions, then a first design. The first consultation is free, in Lao, Thai or English, on WhatsApp or our Facebook page.