Disclaimer: RacewayIQ is an informational engineering tool only. All calculations must be independently verified by the user. Do not rely on these results as the sole basis for design, procurement, installation, construction, permitting, or code compliance decisions.

PoE Power Budget Calculator

Check PoE switch or injector capacity against device power demand, PoE class allocation, spare capacity, and port requirements.

Project and PSE Information

This calculator checks aggregate PoE power budget and planning capacity. Final design must verify per-port PoE standard, negotiated PoE class, device manufacturer power draw, switch power-supply configuration, physical ports, uplinks, and environmental derating.

Project namePSE / switch nameName the PoE switch, injector, midspan, or power supply being checked. This appears in saved calculations and PDF reports.LocationPrepared byDateSwitch model templateUse Custom PSE power budget and enter the available PoE budget from the selected switch, injector, or power supply.Total PSE power budget (W)Use the available PoE budget from switch datasheet, power supply, or PoE license/configuration.Notes

Device Groups

Device Group 1

Device descriptionGroup similar devices, such as fixed cameras, PTZ cameras, APs, phones, card readers, or intercoms.Device typeQuantityNumber of devices in this group.PoE classPoE class allocation is the power a PSE may reserve. Actual device consumption may be lower or higher depending on manufacturer data and negotiated PoE behavior.Manufacturer PD consumption (W)Enter the device datasheet maximum watts. Leave blank only when class-limit budgeting is the best available information.Notes

IEEE standard/type: IEEE 802.3af Type 1PSE class allocation: 15.4 WPD class limit: 13.0 W

Typical devices: IP cameras, intercoms, entry-level wireless access points

Design Criteria

Target spare power capacity (%)Keep margin for future devices, startup behavior, firmware changes, temperature, and switch power-supply variation.PD consumption overhead allowance (%)Applied when manufacturer PD watts are entered. This adds planning margin for conversion, cable, operating, and measurement variation.Total switch portsInstalled / selected switch countReserved uplink portsReserved spare portsPort spare capacity target (%)Separate from PoE power spare capacity. Use for future ports, service ports, and owner spare policy.Redundant power supply reviewed

Default 10% is the industry-standard planning allowance used by this tool for conversion, cable, and operating margin when manufacturer PD watts are entered. Use manufacturer or switch-specific guidance when available. PoE class allocation still governs whenever it is larger.

PSE and PD Definitions

PSE (Power Sourcing Equipment)

Power Sourcing Equipment. The device supplying power over Ethernet, such as a PoE switch, injector, or midspan.

PD (Powered Device)

Powered Device. The device receiving power from a PSE, such as an IP camera, wireless access point, VoIP phone, intercom, or card reader.

PSE budget and PD consumption are not always the same. The PSE may reserve power based on class allocation even when the device uses less power in normal operation.

Power Budget Result

Overall Status: Review Required

PoE power or port capacity passes, but naming, spare capacity, class allocation, utilization, or redundancy assumptions require review.

Review

PSE / Switch

Not entered - add a PSE / switch name for reporting

Total PD count

Required PSE load

15.4 W

Recommended minimum PoE budget

19.3 W

Available PSE budget

370 W

Remaining available power

355 W

Power utilization

4.2%

Spare power capacity

95.8%

Required device ports

Available device ports

Port utilization

2.2%

Port status

Pass

Verify per-port class support, negotiated PoE standard, and manufacturer device consumption in addition to the aggregate PSE budget.

PSE / switch name was not entered. Add a name for clearer saved calculations and PDF reports.

Manufacturer PD consumption was not entered for one or more device groups. PoE class allocation was used for budgeting.

PoE capacity may change with redundant power supply configuration. Verify switch power-supply design and failure mode.

Save and Export

I understand this report is for informational design assistance only and must be independently verified before use.Check this box to enable PDF export.

Save: Log in or create an account to continue.

Export: Create a free account and check the acknowledgement box to export PDF reports.

Device Group Summary

Device group	Type	Qty	Class	PSE allocation/device	Manufacturer PD watts/device	Required PSE load	Notes
Device group 1	IP camera	1	Class 3IEEE 802.3af Type 1	15.4 W	Not entered	15.4 WClass allocation used	None

Device group 1

Quantity: 1
Class: Class 3
PSE allocation: 15.4 W
Manufacturer demand: Not entered
Required load: 15.4 W
Basis: Class allocation used

Calculation Breakdown

PSE / Switch Summary

PSE / switch name: Not entered - add a PSE / switch name for reporting
Available PoE budget: 370 W
Total switch ports: 48
Reserved uplinks: 2
Reserved spare ports: 0
Available device ports: 46

Power Budget

Total manufacturer PD demand: 13.0 W
Total PSE class allocation: 15.4 W
Required PSE load: 15.4 W
Target spare power capacity: 20.0%
Recommended minimum PoE budget: 19.3 W
Remaining available power: 355 W
Power utilization: 4.2%

Port Budget

Required device ports: 1
Available device ports: 46
Port utilization: 2.2%
Port status: Pass

Overall Result

Status: Review Required
Reason: PoE power or port capacity passes, but naming, spare capacity, class allocation, utilization, or redundancy assumptions require review.

PoE Design Considerations

Power

Verify aggregate PoE budget.
Verify per-port PoE class support.
Verify manufacturer device power.

Ports

Verify physical port count.
Confirm uplink reservations.
Confirm spare port policy.

Network

Verify uplink bandwidth separately from PoE.
Confirm VLAN, network, and security requirements separately.

Installation and Expansion

Verify cable length remains within Ethernet limits.
Review cable category, bundling, temperature, and pathway conditions.
Consider future spare capacity, switch licensing, and stacking limits.

Code and Design References

IEEE 802.3 PoE classes and equipment manufacturer data

Class allocations represent maximum PSE output while manufacturer PD watts represent actual device demand at the powered device. Verify negotiated class, per-port limits, cable loss, bundle temperature, power-supply configuration, startup demand, and manufacturer maximum consumption.

Class data is centralized in poeClassData.ts for future standards updates.