WorksheetLow code sensitivityLast reviewed April 29, 2026
Electrical reference chart
kWh Cost Chart
Use this chart for the energy-charge portion of a bill or project estimate before adding demand, delivery, riders, tax, or time-of-use effects.
Quick reference table
kWh cost is the energy portion of an electric bill: kWh x rate. A 500 kWh load at $0.15/kWh costs $75 in energy charges. That is useful for appliance comparisons, lighting retrofits, and runtime estimates, but a real bill can also include demand charges, delivery charges, fixed customer charges, riders, taxes, and time-of-use pricing.
Energy-only monthly cost examples
| Monthly use | $0.10/kWh | $0.15/kWh | $0.20/kWh | $0.30/kWh |
|---|---|---|---|---|
| 50 kWh | $5 | $7.50 | $10 | $15 |
| 250 kWh | $25 | $37.50 | $50 | $75 |
| 500 kWh | $50 | $75 | $100 | $150 |
| 1,000 kWh | $100 | $150 | $200 | $300 |
| 2,500 kWh | $250 | $375 | $500 | $750 |
Which rate should be used for the estimate
| Use case | Rate basis | Bill items to keep separate |
|---|---|---|
| Appliance runtime comparison | Marginal energy rate if available | Fixed customer charge |
| Whole-bill rough check | Average all-in rate from bill | Demand and time-of-use detail |
| Efficiency project | Avoided marginal kWh rate | Demand savings and incentives |
| Commercial process load | TOU or tariff block rate | Demand, ratchet, and riders |
Formula basis
Energy cost = kWh x energy rate per kWh.
- kWh is energy use over the selected period.
- Energy rate is the dollar charge per kWh for that period or tariff block.
Worked examples
Assumptions. Balanced load and line-to-line voltage assumptions behind this chart.
- The chart shows energy charges only and does not model full utility bills.
- Rates can vary by time of use, tariff block, season, utility rider, and customer class.
- Demand charges and fixed charges can dominate commercial bills even when kWh cost looks small.
Code and standard notes. Planning limits that should be checked before final equipment selection.
- For energy economics, verify the current utility tariff, billing period, meter class, project load profile, and any applicable program rules.
- This chart is not tax, rebate, tariff, or investment advice.
How to use this chart
Worksheet checklist. Record source basis, review gaps, and assumptions before using the chart result.
- Record the kWh basisNote whether kWh comes from a bill, meter reading, equipment estimate, appliance label, trend log, or calculated operating schedule.
- Document the rate sourceWrite whether the rate is an average bill rate, marginal energy rate, time-of-use rate, tariff block, or project planning assumption.
- List excluded bill itemsName the bill components excluded from the simple chart so the estimate is not mistaken for a full utility bill forecast.
Common mistakes to avoid. Review these before turning chart current into an equipment decision.
- Comparing project savings with an energy-only rate when demand charges or time-of-use periods drive the real bill impact.
- Using a single average rate for a new load without checking whether the marginal tariff rate is different.
- Treating a simple kWh chart as a financial guarantee instead of a transparent energy-charge calculation.
Frequently asked questions
These answers explain how to use the chart without turning a quick reference into a final design decision.
Why does my bill not match kWh times rate?
Many bills include fixed charges, delivery charges, taxes, riders, demand charges, minimum bills, or time-of-use pricing that are not shown in an energy-only chart.
Should I use average rate or marginal rate?
Use average rate for a rough whole-bill explanation. Use marginal or time-specific rate when estimating the cost of a new load or the savings from reducing a load.
Can this chart estimate commercial savings?
Only the energy portion. Commercial savings may also depend on demand intervals, ratchets, power factor penalties, operational schedule, and tariff details.