Demand Charge Calculator

Background.

Demand Charge Calculator supports a concrete decision: use it to multiply applicable billing demand by tariff rate and billing periods. The result needs one precise interpretation: a demand charge prices the highest or otherwise defined kW interval, not total kWh consumed. The selected relationship is “demand charge = applicable billing demand kW × tariff demand rate × billing periods.”

The editable entries are measured or ratcheted billing demand, tariff demand rate per kw, number of billing periods. Use values from the document or measurement that governs this demand charge question; the defaults are only the worked fixture below. Ratchets, coincident peaks, seasonal rates, power factor and interval length come from the utility tariff. The demand charge calculation does not infer that fact from the other entries.

U.S. Energy Information Administration, Electricity explained—prices and tariffs documents the convention or governing rule used here. The demand charge output is a transparent scenario under those facts: it does not manufacture an unentered market price, professional determination, carrier quote, legal eligibility finding or locally adopted code value.

What is demand charge calculator?

Demand Charge is the relationship behind this decision: a demand charge prices the highest or otherwise defined kW interval, not total kWh consumed. On this page it means demand charge = applicable billing demand kW × tariff demand rate × billing periods. Ratchets, coincident peaks, seasonal rates, power factor and interval length come from the utility tariff; that is the line between the reported quantity and a broader building systems analysis.

How to use this calculator.

1. 01Confirm that “demand charge = applicable billing demand kW × tariff demand rate × billing periods” matches the demand charge convention you need.
2. 02Replace the fixture values for measured or ratcheted billing demand, tariff demand rate per kw, number of billing periods with dated values from the governing record.
3. 03Keep all currencies, measurement units and time periods on the same basis before calculating.
4. 04Read demand charge for entered periods together with this boundary: Ratchets, coincident peaks, seasonal rates, power factor and interval length come from the utility tariff.

The formula.

The calculation uses demand charge = applicable billing demand kW × tariff demand rate × billing periods. In this demand charge model, the entered terms are measured or ratcheted billing demand, tariff demand rate per kw, number of billing periods. A demand charge prices the highest or otherwise defined kW interval, not total kWh consumed, which is why the relationship is presented under this name rather than as a universal alternative. Ratchets, coincident peaks, seasonal rates, power factor and interval length come from the utility tariff. Calculations keep full decimal precision through the relationship and round only the returned display values.

A worked example.

Frequently asked questions.

References& sources.

1. [1]U.S. Energy Information Administration, Electricity explained—prices and tariffs. Retrieved 2026-08-07. access: open unless marked otherwise.
2. [2]U.S. Energy Information Administration. Electric power monthly — average retail price of electricity. Retrieved 2026-08-07. independence: secondary-check; access: open.
3. [3]U.S. Department of Energy. Energy Saver. Retrieved 2026-08-07. independence: primary; access: open.