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Validated Mini-ITX platforms engineered for reliable deployment in industrial, edge, and embedded system environments.
MINI-ITX ENGINEERING TOOL
Mini-ITX DC Power Consumption Calculator
Estimate maximum system load, DC source current, minimum power-supply rating, and a practical supply class from a small set of clearly defined inputs.
Maximum-load power budget
Conversion-efficiency allowance
Supply headroom included
DC POWER PATH
DC Source
12 V / 19 V / 24 V / 48 V
Conversion
Efficiency allowance
Mini-ITX Load
Board, storage, cards, peripherals
Psource = Pload ÷ η
POWER-SUPPLY SIZING
Enter the Maximum Sustained Loads
Use measured or datasheet maximum values. Do not enter CPU TDP alone as total motherboard power.
INPUTS
System Power Budget
W
Use maximum board input power when available.
W
RAM, SSDs, HDDs, and removable storage.
W
PCIe cards, GPU, NPU, NIC, or capture cards.
W
Powered USB devices, cooling, displays, and auxiliaries.
%
Input-bus to system-rail efficiency at maximum load.
%
Additional capacity above estimated maximum source demand.
Input rule: enter maximum sustained loads once. Do not add the same device in more than one field.
TYPICAL NEXT SUPPLY CLASS
120 W class
Choose a supply rated at or above the calculated minimum.
Maximum System Load
85.0 W
Sum of entered load categories
Estimated Source Demand
94.4 W
System load ÷ conversion efficiency
Estimated Source Current
7.87 A
At 12 V before design headroom
Minimum Supply Rating
113.3 W
Source demand plus selected headroom
Minimum Current Rating
9.44 A
Minimum output current at 12 V
Conversion Loss
9.4 W
Estimated source demand minus system load
Preliminary sizing complete
Verify startup current, cable size, connector rating, temperature, and transient response on the finished system.
ACTIVE MODEL
Psupply,min = (ΣPload ÷ η) × (1 + headroom)
CALCULATION METHOD
One Power Budget, Four Transparent Steps
The calculator treats the entered component values as maximum sustained system-rail loads. It then accounts for conversion loss and the selected supply-capacity headroom.
Important: this is a steady-state sizing model. Startup surge and short transients must still be validated on the real hardware.
System Load
Pload = Pboard + Pmemory/storage + Pexpansion + PotherSource Demand
Psource = Pload ÷ ηSource Current
Isource = Psource ÷ VDCMinimum Supply Rating
Psupply,min = Psource × (1 + headroom)INPUT GUIDANCE
Use Values That Match the Real System
Input quality matters more than adding more fields. Use the best available evidence and avoid double counting.
Use Maximum Sustained Power
Prefer measured input power or a qualified platform maximum. CPU TDP alone is not total motherboard power.
Use Load-Point Efficiency
Enter the expected DC/DC efficiency near maximum load. If unknown, use a conservative value rather than a best-case claim.
Keep Practical Headroom
Headroom helps avoid continuous operation at the supply limit. It does not replace startup, transient, or thermal testing.
ENGINEERING SCOPE
Useful for Initial Selection, Not Final Electrical Sign-Off
Use the result to shortlist a DC adapter or supply. Final validation should confirm startup behavior, transient response, wiring loss, connector derating, thermal performance, and protection coordination.
Discuss Your Power RequirementSteady-State Power Budget
Component load, conversion loss, source current, capacity headroom, and minimum supply rating.
Hardware-Specific Conditions
Inrush, short transients, cable ampacity, connector temperature rise, undervoltage behavior, and protection response.
FAQ
DC Power Calculator Questions
Does CPU TDP equal total Mini-ITX system power?
No. Total system power can also include motherboard conversion losses, memory, storage, expansion cards, USB devices, fans, and other powered hardware.
What power value should I enter for each device?
Use maximum sustained input power from measurement or a reliable specification. Enter each load once and avoid mixing typical values with duplicated peak allowances.
Why does efficiency increase the required source power?
The conversion stage dissipates part of the input power as heat. Therefore, source demand is higher than the useful power delivered to the system rails.
How much supply headroom should I use?
Twenty percent is a practical planning default, but the appropriate value depends on load uncertainty, transient behavior, temperature, reliability targets, and the selected supply.
Does this calculator verify startup surge and cable size?
No. It performs steady-state sizing. Startup current, short transients, cable voltage drop, conductor ampacity, connector derating, and thermal performance require separate validation.