A/B Testing PC Power Supply (Annual) Calculator Examples
Worked examples showing how PSU efficiency, PC load, usage time, and electricity prices affect annual running costs.
These examples use the same method as the calculator: estimate wall power for each PSU, calculate annual kWh, and apply an electricity rate. Currency values represent the unit of currency used for the electricity price.
Daily gaming PC: 80% versus 90% efficiency
400 W component load, 5 hours per day, used every day, electricity at 0.16 per kWh.
Input Summary
Component load
400 W
PSU A / PSU B efficiency
80% / 90%
Annual use
1,825 hours
Electricity rate
0.16 per kWh
Calculation Breakdown
- 1Wall power400 / 0.80 and 400 / 0.90500 W and 444.44 W
- 2Annual energyWall power × 1,825 / 1000912.50 kWh and 811.11 kWh
- 3Annual costAnnual kWh × 0.16146.00 and 129.78
Result Summary
Annual cost
146.00 and 129.78
A/B Testing PC Power Supply (Annual) Calculator
PSU B saves an estimated 101.39 kWh and 16.22 per year.
Light-use home PC: modest annual difference
150 W component load, 2 hours per day, 300 days per year, electricity at 0.20 per kWh.
Input Summary
Component load
150 W
PSU A / PSU B efficiency
82% / 90%
Annual use
600 hours
Electricity rate
0.20 per kWh
Calculation Breakdown
- 1Wall power150 / 0.82 and 150 / 0.90182.93 W and 166.67 W
- 2Annual energyWall power × 600 / 1000109.76 kWh and 100.00 kWh
- 3Annual saving(109.76 − 100.00) × 0.201.95
Result Summary
Annual saving
1.95
A/B Testing PC Power Supply (Annual) Calculator
PSU B saves an estimated 9.76 kWh and 1.95 per year.
High-use workstation: larger savings potential
650 W component load, 8 hours per day, 260 days per year, electricity at 0.30 per kWh.
Input Summary
Component load
650 W
PSU A / PSU B efficiency
85% / 94%
Annual use
2,080 hours
Electricity rate
0.30 per kWh
Calculation Breakdown
- 1Wall power650 / 0.85 and 650 / 0.94764.71 W and 691.49 W
- 2Annual energyWall power × 2,080 / 10001,590.59 kWh and 1,438.30 kWh
- 3Annual saving(1,590.59 − 1,438.30) × 0.3045.69
Result Summary
Annual saving
45.69
A/B Testing PC Power Supply (Annual) Calculator
PSU B saves an estimated 152.29 kWh and 45.69 per year.
How to Read Your Results
A positive saving means PSU B is estimated to be cheaper to run than PSU A.
Annual energy difference is shown in kWh; annual cost difference applies your entered electricity rate.
Compare PSUs at the same component load to isolate the effect of efficiency.
Use typical rather than peak load when estimating an average annual cost.
Assumptions & Important Notes
- Each scenario uses a constant average component load while the PC is active.
- The efficiency percentages are treated as applicable at the stated load.
- The displayed electricity rates are illustrative examples, not official or recommended prices.
Related Examples
Frequently Asked Questions
Why are savings larger in the workstation example?
The workstation has a higher load, more annual operating hours, and a higher electricity rate, so each watt of reduced wall power has more annual value.
Can I use a gaming PC's peak load for this calculation?
You can, but it will estimate a peak-load scenario. An average measured or estimated load is usually more useful for annual costs.
Are the example currencies tied to a specific country?
No. The cost figures use generic currency units based on the entered rate per kWh.
Ready to calculate your own result?
Use the live calculator with your own inputs, timing, and preferences.