Where do I find my rate per unit?

On your most recent utility bill, look for the per-unit charge: $/kWh for electricity, $/therm for natural gas, or $/gallon (or $/CCF) for water. Some providers split into supply and delivery — sum them for total rate.

What counts as a fixed fee?

Anything billed monthly regardless of usage — connection charge, customer charge, meter rental, base service fee. Enter the sum of these as a single number.

Does the calculator handle tiered pricing?

No — it uses a single flat rate. If you have tiered or time-of-use pricing, calculate each tier separately and add the totals, or use your average rate for a rough estimate.

On your bill, look for the difference between current and previous meter readings. Electricity is in kWh, gas in therms (or sometimes CCF — 1 CCF ≈ 1.038 therms), water typically in gallons or cubic feet.

Is my bill data sent anywhere?

No. All math runs locally in your browser. Nothing is uploaded, logged, or saved.

Utility Bill Calculator

Estimate an electricity, gas, or water bill from usage, rate, fixed fee, and tax percentage.

Written by Golam Rabbani, Founder & Lead Engineer

This interactive tool requires JavaScript. Read the formula and worked example below; you can compute the result by hand.

How to use this utility bill calculator

Choose a utility type: Electricity, Gas, or Water.
Enter your usage for the period (kWh for electricity, therms for gas, gallons for water).
Enter the rate per unit from your provider's tariff.
Enter any fixed connection/customer charge and the applicable tax %.
Press Calculate to see the total bill with usage, fixed fee, and tax broken out.

About this utility bill calculator

The utility bill calculator turns four numbers — usage, rate, fixed fee, and tax — into the same bill total your provider would print, without having to wade through the actual invoice. It supports electricity (kWh), natural gas (therms), and water (gallons), letting you sanity-check a bill, compare a new tariff, or estimate the cost of running an appliance.

Worked example: an electricity bill for 750 kWh at $0.14/kWh, with a $12 fixed customer charge and a 6% utility tax. Usage cost = 750 × 0.14 = $105.00. Subtotal = 105.00 + 12.00 = $117.00. Tax = 117.00 × 0.06 = $7.02. Total = $124.02. Switching the same usage to a competing $0.12/kWh tariff would drop the bill to $107.22 — a $16.80 monthly difference.

Rates and structures vary by provider and region (tiered pricing, time-of-use, demand charges); this tool models a flat per-unit rate plus a fixed fee, which matches most residential bills.

FAQ

Where do I find my rate per unit?: On your most recent utility bill, look for the per-unit charge: $/kWh for electricity, $/therm for natural gas, or $/gallon (or $/CCF) for water. Some providers split into supply and delivery — sum them for total rate.
What counts as a fixed fee?: Anything billed monthly regardless of usage — connection charge, customer charge, meter rental, base service fee. Enter the sum of these as a single number.
Does the calculator handle tiered pricing?: No — it uses a single flat rate. If you have tiered or time-of-use pricing, calculate each tier separately and add the totals, or use your average rate for a rough estimate.
How do I find usage?: On your bill, look for the difference between current and previous meter readings. Electricity is in kWh, gas in therms (or sometimes CCF — 1 CCF ≈ 1.038 therms), water typically in gallons or cubic feet.
Is my bill data sent anywhere?: No. All math runs locally in your browser. Nothing is uploaded, logged, or saved.