Illustrative flat rate: $0.10/kWh. Constant 3 kW device load; 24 hours/day; 30 days. Energy-only, not a bill or profit forecast.
The simple calculation
For a constant load, energy in kWh equals power in kW multiplied by operating hours. A fictional 3 kW device operating for 24 hours uses 72 kWh. At an assumed flat $0.10/kWh, its energy-only cost is $7.20 for that day.
The example above lets you compare three hypothetical flat rates. It does not ask for personal information, use market prices, estimate your bill, or calculate mining profit. Every selected rate is an authored scenario.
Make the time window explicit
Thirty assumed days are 720 hours. That same constant 3 kW load would use 2,160 kWh, producing a $216 energy-only example at the stated rate. An actual billing period may use different dates, changing power, or different charges.
The full electricity-cost guide shows how to segment changing loads rather than multiplying a brief peak observation by an entire month.
Decide where the boundary sits
Device power may exclude external fans, pumps, networking, or other facility equipment. A site-level meter may already include them. Draw the boundary before adding line items so the model neither omits important consumption nor counts it twice.
When comparing two setups, use the same boundary. A lower device-only figure is not proof of a lower whole-site result.
A tariff is more than an example rate
Review the actual agreement and invoice applicable to the site. Identify the energy, delivery, demand-related, fixed, tax, or other components that genuinely apply. Keep unknown fields unresolved until supported by the agreement or provider explanation.
Do not infer electrical installation requirements from this arithmetic. Suitable equipment, circuits, protective devices, and measurement arrangements require manufacturer guidance and qualified review.
Keep observed costs separate from forecasts
Record measured power, operating intervals, and verified charges separately from hypothetical revenue. A cost reduction caused by less runtime is not by itself proof of a better overall business result.
Use the cost planning framework to document assumptions and the efficiency guide to understand compatible ratios. No investment recommendation is made by these examples.