Private in-browser planning
Electricity Rate Comparison Calculator
Starting values are hypothetical. Replace them with your own figures. Inputs stay in this browser and are not included in the energy inquiry.
- Enter total period kWh once. Months multiply monthly fees only.
- This compares the stated supply scope, not an entire utility tariff.
Prepare a fair set of offer inputs
Choose one comparison period, such as the next twelve months, and enter the total electricity you expect to consume during it. The months field counts recurring monthly fees; it does not multiply consumption again. For a one-year comparison, annual kWh belongs in the usage box and twelve belongs in the months box. For a six-month term, use six months of expected usage.
Transcribe the energy rate from each actual offer. Confirm whether a broker fee, capacity component, transmission item, line loss allowance or renewable product is already in that rate. If one offer passes an item through and another includes it, a simple headline-rate comparison is incomplete. Obtain a comparable cost schedule before relying on the numerical difference.
The formula and a worked example
For each offer, modeled supply cost is period kWh multiplied by dollars per kWh, plus monthly supplier fees multiplied by the entered months. Effective supply rate is that modeled cost divided by period kWh. When consumption is zero, the tool can still show recurring fees, but an effective per-kWh rate is not defined.
Suppose a hypothetical account uses 120,000 kWh in twelve months. Offer A at $0.10 per kWh with no fee costs $12,000. Offer B at $0.095 with a $25 monthly fee costs $11,700. B’s effective supply cost is $0.0975 per kWh, and the modeled difference is $300. The added fee absorbs half of the apparent $600 energy-rate advantage.
How to read the signed difference
The difference is labeled A minus B. A positive value means B costs less within the inputs; a negative value means A costs less. That convention avoids forcing a savings claim when the second offer is more expensive. It also makes it easier to reproduce the result in a procurement worksheet without guessing which option the calculator called current.
Do not compare a one-year fixed product with a shorter variable offer as though their terms were equivalent. Future index prices are unknown, and a longer period of price certainty may have a different value to your budget. For a variable product, run several explicit price cases instead of entering one rate and treating the output as a forecast.
What still needs contract and bill review
This model excludes delivery, demand, taxes and other charges unless you deliberately incorporate comparable supplier items in the fields. It does not evaluate credit requirements, early termination provisions, automatic renewal, minimum usage, bandwidth or changes after a promotional period. Those terms can outweigh a small modeled rate advantage.
Retain the offer documents, quote timestamp, assumed load and delivery dates with your calculation. Then compare a complete bill projection and confirm the switching process for the utility account. Use the bill component estimator for an illustrative total, and the contract break-even calculator when changing suppliers could trigger a fee or other one-time cost.
Sources & scope
Primary references reviewed October 15, 2026. These sources support the stated concepts; actual tariffs, program rules and signed agreements govern the account. Decision examples and operational worksheets are original educational analysis.
- DOE FEMP: Evaluating Your Utility Rate Options
Energy charges, demand charges, fixed charges and tariff structures; practical limits of simplified rate calculations.