A/B Testing PC Power Supply Monthly Calculator Examples
Worked examples showing how PC load, PSU efficiency, usage time, and electricity price affect monthly electricity costs.
These examples compare common PC power scenarios using estimated component load, power supply efficiency, daily running time, and a single electricity rate.
Same gaming PC with two PSU efficiencies
A 350 W PC runs for 6 hours per day over a 30-day month at $0.18 per kWh.
Input Summary
Scenario A
350 W load, 85% efficiency, 6 hours/day
Scenario B
350 W load, 92% efficiency, 6 hours/day
Electricity price
$0.18 per kWh
Days
30
Calculation Breakdown
- 1Scenario A energy(350 / 0.85) / 1000 * 6 * 3074.12 kWh
- 2Scenario A cost74.12 * 0.18$13.34
- 3Scenario B energy(350 / 0.92) / 1000 * 6 * 3068.48 kWh
- 4Scenario B cost68.48 * 0.18$12.33
Result Summary
Scenario B cost
$12.33
A/B Testing PC Power Supply Monthly Calculator
Scenario B costs about $1.01 less per month in this estimate.
Work PC with lower daily use
Both scenarios use an 80% efficient PSU and electricity costs $0.20 per kWh.
Input Summary
Scenario A
120 W load, 8 hours/day, 80% efficiency
Scenario B
120 W load, 3 hours/day, 80% efficiency
Electricity price
$0.20 per kWh
Days
30
Calculation Breakdown
- 1Wall power120 / 0.80150 W
- 2Scenario A cost150 / 1000 * 8 * 30 * 0.20$7.20
- 3Scenario B cost150 / 1000 * 3 * 30 * 0.20$2.70
Result Summary
Scenario B cost
$2.70
A/B Testing PC Power Supply Monthly Calculator
The shorter-use scenario costs about $4.50 less per month.
Higher-load rendering PC comparison
A rendering workstation is compared with a more power-efficient hardware configuration.
Input Summary
Scenario A
700 W load, 90% efficiency, 5 hours/day
Scenario B
580 W load, 90% efficiency, 5 hours/day
Electricity price
$0.25 per kWh
Days
30
Calculation Breakdown
- 1Scenario A cost(700 / 0.90) / 1000 * 5 * 30 * 0.25$29.17
- 2Scenario B cost(580 / 0.90) / 1000 * 5 * 30 * 0.25$24.17
- 3Monthly difference29.17 - 24.17$5.00
Result Summary
Monthly difference
$5.00
A/B Testing PC Power Supply Monthly Calculator
Scenario B is estimated to cost $5.00 less per month.
How to Read Your Results
Monthly energy is shown in kWh, the unit generally used for electricity billing.
A lower monthly cost indicates the lower-cost scenario for the entered assumptions.
A negative value for B compared with A means Scenario B is estimated to cost less.
The potential saving is the cost gap, not a guaranteed bill reduction.
Compare scenarios using the same month length and electricity price for a like-for-like result.
Assumptions & Important Notes
- Each scenario uses a constant average component load during its entered daily runtime.
- The supplied electricity price is a representative per-kWh rate.
- All active operating hours are treated alike; idle and high-load periods are not modeled separately.
Related Examples
Frequently Asked Questions
Can I compare two different PC builds?
Yes. Enter each build's typical component load, PSU efficiency, and daily use time as separate scenarios.
Can I compare gaming and idle use?
Yes, if each scenario represents a distinct average load and usage pattern. For a mixed day, use a weighted average load or calculate periods separately.
Why are results in kWh instead of watts?
Watts measure instantaneous power, while kWh measures energy used over time and is typically used to calculate electricity charges.
Should I use 30 or 31 days?
Use the number of days you want the monthly estimate to cover.
Ready to calculate your own result?
Use the live calculator with your own inputs, timing, and preferences.