California Electricity Bill Calculator accuracy and testing

Formula source

• Estimated bill = tier 1 kWh x tier 1 rate + tier 2 kWh x tier 2 rate + fixed charges - bill credits.

Test cases

Known limitations

• Planning estimate only; not tax, legal, insurance, utility, financial, or real estate advice. Verify current local rules, policies, rates, exemptions, caps, exceptions, official notices, utility tariffs, insurance declarations, and qualified advisors before relying on any result. This does not model live tariffs, time-of-use windows, baseline allowances, net billing, demand charges, public purpose programs, or rate assistance eligibility.

Assumptions

• All rates, caps, windows, premiums, and charges are editable planning examples.
• No live local tax, utility, rent, legal, insurance, or program rate is fetched or guaranteed.
• Calculations run client-side in the browser and are based only on the values entered.

Unit handling

• Electricity Rate Preset accepts one of the configured options.
• Monthly Usage accepts values in kWh.
• Tier 1 Limit accepts values in kWh.
• Tier 1 Rate accepts values in $/kWh.
• Tier 2 Rate accepts values in $/kWh.
• Fixed Charges accepts values in $.
• Bill Credits accepts values in $.
• Estimated Monthly Bill is displayed as currency.

Rounding rules

• Number displays use up to 2 decimal places in the calculator UI.
• Currency outputs are displayed with standard US dollar formatting.
• Input precision follows configured step values where provided.

Version history

Change log