Commercial Electricity Bill Calculator

How the commercial electricity bill calculator works

First-tier kWh is the smaller of imported energy and the first-tier allowance. Remaining kWh uses the second-tier rate. The threshold applies once to the whole billing period. Each tier charge rounds half-up to cents before they are summed.

Demand charge = entered billable kW × demand rate, rounded separately. Add the separately rounded fixed fee. Tax is the entered percentage of the full rounded subtotal, rounded to cents and added to get total bill. Total bill divided by energy is unavailable at zero kWh; fixed and demand charges can still remain.

This is an entered-term bill scenario, not a utility-rate lookup. Billable demand must already reflect the actual interval rules, ratchets, minimums and power-factor treatment. Time-of-use calendars, exports, special taxes, exclusions, further tiers and credits are omitted. Confirm that taxing the whole modeled subtotal matches the intended comparison. SAM documents the broader range of actual tariff components.

Worked example

12,000 kWh with a 5,000 kWh first tier costs 600 at 0.12/kWh and 700 at 0.10/kWh. Billable demand of 40 kW at 15/kW adds 600. A 50 fixed fee gives 1,950 before tax; 5% adds 97.50 for a 2,047.50 total. At 6,000 kWh with the other terms unchanged, total is 1,417.50.

Sources and assumptions

The source material explains the underlying calculation or pricing structure. Entered prices, costs, schedules and scenario choices are your assumptions; this tool does not obtain supplier quotes or predict actual results.

• System Advisor Model: electricity energy, demand and fixed charges