How is a utility demand charge calculated?

Multiply your billing peak demand in kW by the demand rate in $/kW, adjust for any partial billing applicability, and add fixed fees. With 920 kW at $18.50/kW fully applicable plus $450 fixed, the total is $17,470.

What is the difference between demand charges and energy charges?

Energy charges bill total kWh consumed over the month; demand charges bill your single highest instantaneous power draw in kW. You can use the same energy but cut the demand charge by smoothing that peak.

How can I reduce my demand charge?

Stagger large motor starts, shift batch loads off the peak window, run a battery to shave the spike, or curtail during demand-response events. Even shaving 50 kW off a 920 kW peak at $18.50/kW saves about $925 a month.

What is a demand ratchet?

A ratchet sets your billed demand to a percentage of your highest peak over the prior 11-12 months, so one bad spike inflates bills for a year. This calculator models the current peak; check your tariff for ratchet clauses.

What does billing applicability mean here?

It is the fraction of the demand that the tariff actually bills in this period, used for partial months, prorated service, or a ratchet percentage. The default 100% bills the full measured peak.

Why is the per-kW figure higher than the rate?

Because fixed demand-related fees are spread across the billed kW. The example shows $18.99 per billed kW versus the $18.50 rate, the difference being the $450 of fixed fees.

Energy & Sustainability calculator

Utility Demand Charge Calculator

For industrial plants, the demand charge, billed on your single highest 15-minute peak, can rival or exceed the energy charge on the electric bill. This calculator multiplies your billing peak demand by the demand rate, applies any partial-billing ratchet, and adds fixed fees to estimate the demand portion of the bill. Plant energy managers and facilities teams use it to quantify what a peak-shaving project, load shift, or battery is worth. Because the charge keys off a brief peak, trimming a few kW off that spike drops straight to the bottom line.

What this calculator does

Estimate monthly utility demand charge from billing peak kW, demand rate, billing applicability, and fixed utility fees.
a facility or utility manager needs to estimate demand charges from monthly peak kW
It computes the demand portion of a utility bill: peak kW times the demand rate, scaled by billing applicability, plus fixed demand-related fees.

Formula used

Variable demand charge = billing peak demand × demand charge rate × billing applicability
Total utility demand charge = variable demand charge + fixed demand-related fees

Inputs explained

Billing peak demand:
Demand charge rate:
Billing applicability:
Fixed demand-related fees:

How to use the result

Use it to estimate the value of peak shaving, demand response, or load shifting before approving a project, or to sanity-check a monthly demand charge.
It models a single billing period and rate; it does not capture demand ratchets that lock in past peaks, time-of-use demand windows, or tiered rates, which your tariff may impose.

Current U.S. benchmarks

Industrial electricity averages 8.66 cents per kWh across the U.S. (EIA, Apr 2026), up 5.5% from a year earlier. Energy-intensive steps carry this directly into unit cost.

Common questions

How is a utility demand charge calculated? Multiply your billing peak demand in kW by the demand rate in $/kW, adjust for any partial billing applicability, and add fixed fees. With 920 kW at $18.50/kW fully applicable plus $450 fixed, the total is $17,470.
What is the difference between demand charges and energy charges? Energy charges bill total kWh consumed over the month; demand charges bill your single highest instantaneous power draw in kW. You can use the same energy but cut the demand charge by smoothing that peak.
How can I reduce my demand charge? Stagger large motor starts, shift batch loads off the peak window, run a battery to shave the spike, or curtail during demand-response events. Even shaving 50 kW off a 920 kW peak at $18.50/kW saves about $925 a month.
What is a demand ratchet? A ratchet sets your billed demand to a percentage of your highest peak over the prior 11-12 months, so one bad spike inflates bills for a year. This calculator models the current peak; check your tariff for ratchet clauses.
What does billing applicability mean here? It is the fraction of the demand that the tariff actually bills in this period, used for partial months, prorated service, or a ratchet percentage. The default 100% bills the full measured peak.

Last reviewed 2026-05-12.