Electricity Bill Calculator

Your electricity bill equals your kilowatt-hours used times your rate, plus the fixed monthly service charge. For 900 kWh at $0.17/kWh with a $10 service fee: 900 × 0.17 = $153 energy charge, plus $10 = $163 for the month, about $1,956 a year. The calculator above returns the full bill, the energy charge on its own, the annual total, and your average daily usage.

Most utility bills have exactly two parts: a variable energy charge that scales with how much you use, and a fixed charge (also called a customer, service, or basic charge) that you pay no matter what. Because both come straight from your own bill in this calculator, the estimate is personalized to your utility rather than a national guess — the whole point of a tool you feed with your real numbers.

The two-part structure is captured in one equation:

The first term is your energy charge: the utility measures the kilowatt-hours your meter recorded and multiplies by the per-kWh rate. The second term is the fixed charge, a flat fee that covers metering, billing, and grid connection regardless of usage. Working the default example:

• Energy charge: 900 kWh × $0.17 = $153.00.
• Fixed charge: $10.00.
• Total bill: $153.00 + $10.00 = $163.00.

The fixed charge matters more at low usage. If you use only 100 kWh, a $10 fixed fee is over a third of a $27 bill; at 2,000 kWh it barely registers. This is also why your effective rate (total ÷ kWh) is always a little higher than the posted per-kWh rate. To find how many kilowatt-hours a given appliance adds to that usage number, use the energy usage calculator, and to price a specific block of kWh use the kWh cost calculator.

These examples show how usage, rate, and fixed charges combine into a final statement.

Example 1 — An average US household. The typical American home uses about 900 kWh a month. At $0.17/kWh with a $10 service charge: energy = 900 × 0.17 = $153; total = $163. Annualized that is $1,956 — close to the national average of roughly $1,800–$2,000.

Example 2 — A small efficient apartment. 300 kWh a month at $0.15/kWh with a $12 fixed charge: energy = 300 × 0.15 = $45; total = $57. Notice the fixed charge is 21% of this bill, so the effective rate is $0.19/kWh — well above the posted $0.15.

Example 3 — An all-electric home in winter. 1,800 kWh at $0.14/kWh with an $18 fixed charge: energy = 1,800 × 0.14 = $252; total = $270. Heating drives usage up in cold months; running this for each season shows how much of the annual bill is seasonal.

Example 4 — High-rate coastal utility. 700 kWh at $0.31/kWh with a $10 charge: energy = 700 × 0.31 = $217; total = $227. The same 700 kWh in a low-cost state would cost under $90 in energy — a stark illustration of why entering your own rate is essential.

A bill estimate is only as good as its three inputs, and all three are things only you can supply from your own statement:

• Your usage (kWh). Read it from the "kWh used" line on your bill, or estimate it by adding up your appliances with the appliance running cost calculator. Usage swings with season, occupancy, and weather.
• Your rate ($/kWh). Utilities post a base rate, but your real per-kWh cost includes delivery, transmission, riders, and taxes. Divide a past bill's total by its kWh to get the blended rate to enter here.
• Your fixed charge. Look for a line labeled customer charge, basic service charge, or facilities charge. It ranges from about $5 to $30 a month depending on utility and rate plan.

Because you provide all three, this calculator reflects your utility's specific pricing, not an average that could be wildly off. That personalization is exactly what a generic online figure — or an AI that cannot see your bill — cannot deliver. Once your inputs reproduce a past bill accurately, you can trust the tool to forecast future months by adjusting only the usage figure.

The single-rate model here covers most flat-rate customers, but many utilities use more complex pricing. Knowing which you are on tells you what rate to enter.

Flat rate. One price per kWh all month. Enter that rate directly; the calculator is exact.

Tiered (inclining block) rates. The price rises after you cross monthly thresholds — for example $0.14 for the first 500 kWh, $0.20 above that. If most of your usage sits in one tier, enter that tier's rate; if it straddles tiers, enter a weighted blended rate (total energy charge ÷ total kWh from a recent bill).

Time-of-use (TOU) rates. The price depends on the hour — peak, off-peak, and sometimes a mid-peak. For a whole-bill estimate, use your blended average rate. To evaluate shifting load to cheaper hours, run the calculator twice with the peak and off-peak rates and compare.

Demand charges. Rare for residential customers but common commercially, these bill your highest 15-minute power draw (kW), separate from energy (kWh). This calculator handles the energy and fixed portions; add any demand charge separately if your bill has one. For most homes, the two-part energy-plus-fixed model here is complete.

1. Enter your monthly usage in kWh. Copy it from the "total kWh used" line on a recent bill, or build it up from appliances.
2. Enter your rate. Use your blended rate: a past bill's total (minus the fixed charge) divided by its kWh, or just total ÷ kWh for an all-in figure.
3. Enter the fixed monthly charge. Find the customer or basic service charge on your bill; a common default is $10.
4. Read the results. The monthly bill is primary; you also see the energy charge alone, the annual bill, and average daily kWh for sanity-checking.

To forecast next month, keep your rate and fixed charge the same and adjust only the usage. To test a conservation goal — say cutting usage 15% — reduce the kWh figure and watch the bill fall.

Once the calculator matches your real statement, it becomes a planning tool. Because the energy charge is simply usage × rate, only two levers change it: use fewer kilowatt-hours, or pay less per kilowatt-hour.

Cutting usage. The largest reductions come from the largest loads — heating and cooling, water heating, and, in all-electric homes, cooking and drying. Lowering a thermostat a few degrees, adding insulation, switching to a heat pump, and shifting to LED lighting all reduce the kWh number you enter. Model the target usage here to see the dollar impact before committing to any upgrade.

Cutting the rate. If your utility offers time-of-use pricing and you can move flexible loads (EV charging, dishwasher, laundry, pool pump) to off-peak hours, your blended rate falls. Community solar, rooftop solar, or a competitive supplier in deregulated markets can also lower the per-kWh figure. Enter the new rate to quantify the saving.

The fixed charge is largely out of your control — it is the price of being connected — which is why very low usage yields diminishing returns: you can never get the bill below that floor. This is worth remembering before investing heavily to shave the last few kilowatt-hours. To attribute usage to specific devices, pair this with the electricity cost calculator and power consumption calculator.

To use this calculator well, it helps to know where each number lives on a typical utility statement. Bills vary by provider, but nearly all share the same core lines.

Total kWh used. Usually near the top or in a usage summary, sometimes shown as the difference between this month's and last month's meter readings. This is the figure to enter as monthly usage.

Energy or supply charge. The variable part, often broken into generation and sometimes a separate delivery charge. Dividing the total energy charge by kWh used gives your energy rate; dividing the entire bill by kWh gives your all-in blended rate.

Fixed, customer, or basic service charge. A flat monthly line that does not change with usage. Enter this as the fixed charge. Some utilities bury it inside a "delivery" section, so scan carefully.

Taxes, riders, and surcharges. Municipal taxes, renewable-energy riders, and fuel-adjustment charges. These are captured automatically when you use a blended rate derived from the bill total. If you enter only the base energy rate, your estimate will run low. Reading the bill once and identifying these lines lets you set the calculator's inputs so accurately that it reproduces the statement almost to the penny — after which it becomes a reliable forecasting tool for future months.

• Forgetting the fixed charge. Leaving it at zero understates every bill and makes low-usage months look cheaper than they are.
• Using the base rate instead of the blended rate. Delivery, riders, and taxes can add 30–50%; use total ÷ kWh from a real bill.
• Ignoring tiers. On an inclining-block plan, high-usage months push kWh into a pricier tier; use a weighted rate.
• Assuming flat usage year-round. Heating and cooling make winter and summer bills far higher than spring and fall; estimate month by month.
• Mixing billing-cycle lengths. A 33-day cycle costs more than a 28-day one at the same daily rate; match the days if reconciling exactly.

Handle the fixed charge and blended rate correctly and this calculator will reproduce a past bill within a dollar or two, giving you confidence in its forecasts.