Free Electricity Cost Calculator
Updated September 2026
Calculate electricity cost for any appliance based on wattage, hours of use, and rate per kWh. Find monthly and annual energy costs — free online tool.
Verified Capabilities
Computes daily energy usage (kWh) plus daily, monthly, and annual cost from wattage, hours, days, and rate.
Days per Month is an editable field (defaults to 30), not a fixed assumption.
Switch the displayed currency symbol across 40+ world currencies from the dropdown.
Annual Cost is always Daily Cost × 365 and does not use your Days per Month value — it can overstate annual cost for appliances not used every day of the year.
Whether you're planning finances, comparing options, or verifying numbers, having an accurate calculator ready saves time and prevents costly mistakes.
Calculate electricity cost for any appliance based on wattage, hours of use, and rate per kWh. Find monthly and annual energy costs — free online tool. Results are immediate — no waiting, no loading screens, no account required.
Who uses the Electricity Cost Calculator?
- Homeowners identifying which appliances are driving up their electricity bill.
- Renters estimating monthly utility costs before signing a lease.
- Energy-conscious users calculating payback period on energy-efficient appliances.
Common uses and search terms
The Electricity Cost Calculator is frequently used for: electricity cost, kWh, energy bill. Whether you need a quick result or are working through a longer project, the tool handles all common variations without any configuration.
Accuracy and formula transparency
The Electricity Cost Calculator uses a validated formula consistent with published standards from recognised financial and mathematical authorities. All arithmetic is performed with 64-bit IEEE 754 floating-point precision — the same standard used by Microsoft Excel, Google Sheets, and professional financial software. Rounding, if applied, follows standard half-up convention unless stated otherwise. Inputs and results are processed entirely in your browser; no data is transmitted to any server. For consequential financial or legal decisions, always verify results with a qualified professional.
Why use Allio Tools's Electricity Cost Calculator?
Everything runs locally in your browser. No data is sent to a server, logged, or stored anywhere. The tool is completely free with no usage limits, no premium tiers, and no account required. Available in 11 languages and optimised for all screen sizes, the Electricity Cost Calculator works on desktop, tablet, and mobile with no app download needed.
See also:Mortgage Calculator · Currency Converter · Loan Calculator
How the Electricity Cost Calculator works
Enter the appliance's power draw in watts in the Power (Watts) field (found on the device label or manual).
Enter how many hours per day you use the appliance in the Hours per Day field.
Enter how many days per month you use it in the Days per Month field (defaults to 30).
Enter your electricity rate in the Cost per kWh field (a plain number in your currency per kWh, e.g. 0.16 for $0.16/kWh — not cents), then click Calculate to see daily, monthly, and annual cost plus daily energy usage in kWh.
Tips & tricks
- Annual Cost is always Daily Cost × 365 — it does NOT use your Days per Month value, so it can overstate your real annual cost if you don't use the appliance every day of the year.
- Cost per kWh should be entered as a plain rate in your currency (e.g. 0.16 for $0.16/kWh), not in cents — entering 16 would be read as $16/kWh, not 16 cents.
- Days per Month only affects the Monthly Cost figure, not Daily Cost or Annual Cost — it defaults to 30 but can be changed to match your actual usage pattern.
- For appliances that run continuously (like refrigerators), enter 24 in Hours per Day rather than leaving it blank — the daily usage figure assumes whatever you enter is genuinely how many hours it draws power.
Frequently Asked Questions
How do I calculate electricity cost for an appliance?
Energy (kWh) = Watts ÷ 1000 × Hours. Cost = kWh × price per kWh. Example: a 1,500W heater running 4 hrs/day at $0.16/kWh = 6 kWh/day × $0.16 = $0.96/day. The calculator does this instantly and also multiplies by your Days per Month for a monthly figure.
What is the average electricity rate in the US?
The US average is roughly $0.16 per kWh. Hawaii is highest (~$0.42/kWh), Louisiana lowest (~$0.10/kWh). Check your utility bill for your exact rate and enter it in the Cost per kWh field.
How much does it cost to run a refrigerator per month?
A modern refrigerator uses 100–400 watts but runs continuously at roughly a 1/3 duty cycle, so about 30–130 kWh/month. At $0.16/kWh that's $5–$21/month. Check the EnergyGuide label on your specific model, or estimate an average wattage and enter 24 hours/day here.
What is a kWh and how is it different from watts?
Watts measure power (rate of energy use). kWh measures energy consumed over time. 1 kWh = 1,000 watts used for 1 hour. Your electric bill charges you per kWh consumed, not per watt — this is why the calculator asks for a Cost per kWh rate, not a per-watt rate.
Does changing Days per Month affect the Annual Cost shown?
No — Annual Cost is always calculated as Daily Cost × 365, regardless of what you enter in Days per Month. That field only scales the Monthly Cost figure. If your appliance isn't used every single day of the year, the Annual Cost will be an overestimate; adjust it yourself by multiplying Daily Cost by your actual annual usage days instead.
Which household appliances use the most electricity?
Highest consumers: electric water heater (~4,000W), central AC (3,000–5,000W), electric dryer (~5,000W), oven (2,000–5,000W), space heater (~1,500W). Lighting and phone chargers are minimal in comparison.
Is my data safe when using the Electricity Cost Calculator?
Completely safe. The Electricity Cost Calculator processes everything locally in your browser. No input data, results, or usage information is ever transmitted to or stored on any server.
How accurate are the Electricity Cost Calculator results?
The Electricity Cost Calculator uses standard, well-established mathematical formulas used by professionals worldwide — the same ones used by banks, financial advisors, and accounting software. Results are as accurate as the inputs you provide. See our <a href="/methodology/">Methodology page</a> for formula sources and references. For financial decisions, always verify with a qualified professional.
Can I share the Electricity Cost Calculator results with someone?
Yes. Copy the result number or screenshot the page to share via message, email, or social media. You can also bookmark and share the tool URL directly — the Electricity Cost Calculator opens instantly for anyone with a modern browser, no account needed.
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