Business and Financial Tools
Appliance Electricity Cost Calculator
Estimate energy by appliance and cost using an entered average rate or an incremental PEA bill.
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See where your electricity goes
Appliance Electricity Cost Calculator
Add appliances, set their power and usage, and estimate costs.
Energy by appliance
| Appliance | W | Qty | Hours/day | Duty | kWh |
|---|
Energy = watts × quantity × hours/day × days × duty fraction / 1,000. Each device rounds to six kWh decimals before summing. Average-rate cost rounds to satang. PEA mode compares bills before/after adding total energy rounded to 0.01 kWh, preserving tariff, fee, Ft and VAT. It does not determine assistance or automatic tariff changes. This is not a measurement and excludes TOU, MEA, solar offsets and reverse metering. Reports include your entered appliance names.
Quick answer
How much electricity does each appliance use?
Energy in kWh = watts × quantity × hours per day × days × duty fraction / 1,000. Use actual power and usage assumptions; defaults are illustrative. Multiply energy by an entered average rate or compare PEA bills before and after adding the listed consumption.
How to use this tool
- Edit illustrative devices or add/remove rows, from 1 to 20. Enter watts, quantity, daily on-time and duty.
- Set duty to 100% when entering measured average power. BTU is not electrical input watts.
- Choose days and an entered tax-inclusive average rate or incremental PEA model. PEA other consumption must exclude the listed devices.
- Calculate and review device energy and cost. Print, Excel, PDF and TXT reports include entered appliance names.
How the calculation works
Fixed-scale integer arithmetic rounds each device to six kWh decimals before summing. Average-rate cost includes assumed tax and rounds half-up to satang. PEA mode rounds total added consumption to 0.01 kWh and adds it to other consumption excluding these devices, using the same residential bill model as the existing PEA calculator. Tariff, service fee, Ft and VAT remain unchanged between bills. Twelve-period cost repeats identical assumptions twelve times.
Examples
| Example | Input | Expected result |
|---|---|---|
| Illustrative fan | |
14.4 kWh and estimated cost THB 64.80. |
| Three illustrative devices | |
174.24 kWh; cost THB 784.08 at 4.50/kWh; THB 9,408.96 for twelve identical periods. |
| Add devices to 300 kWh of other consumption | |
Baseline bill THB 1,179.94; combined bill 2,001.36; incremental cost THB 821.42. |
Limitations
- A power/time model, not a meter reading. Excludes changing loads, weather, starting current and certified efficiency performance.
- Supports 1–20 rows; watts 0–500,000, hours/day 0–24, duty 0–100%, up to two decimals; quantities whole 1–1,000; days whole 1–31; total consumption up to 1,000,000 kWh.
- Average rates accept THB 0–100/kWh and include assumed tax. PEA added energy rounds to 0.01 kWh, slightly differing from the six-decimal energy display when necessary.
- PEA base rates start Sep 2026; default Ft is Sep–Dec 2026. Editable fee defaults refer to Nov 2018. Check actual bills. Excludes assistance eligibility, MEA, TOU and solar offsets.
- Twelve-period cost holds days, usage and rates fixed. It is not a forecast or an actual annual bill.
Frequently asked questions
Is duty an efficiency rating?
It models the fraction of on-time drawing the entered power, such as cycling compressor operation. It is not efficiency or guaranteed savings. Use 100% with measured average watts.
Is THB 4.50 an official current tariff?
It is an illustrative average-rate assumption. Change it to your own tax-inclusive average. This mode does not apply progressive bands or add VAT again.
Can I enter my whole existing bill consumption in PEA mode?
Other consumption must exclude the listed devices. If your whole bill already includes them, adding the same devices again would double-count them.
Can AC BTU replace watts?
Cooling capacity in BTU/hour is different from electrical input power. Use the electrical W figure from actual documentation or measurement.
Are appliance names and values stored?
They remain in browser memory without server submission or local storage. Names appear in reports only when you choose to export.
References
- Virginia Cooperative Extension — ประมาณพลังงานเครื่องใช้ / Estimating appliance energy Verified 2026-10-06
- PEA — อัตราฐานเริ่มกันยายน 2569 / September 2026 base tariffs Verified 2026-10-06
- กกพ. — เอกสารค่า Ft / Ft by period Verified 2026-10-06
- PEA — ตารางค่าบริการพฤศจิกายน 2561 / November 2018 service-fee reference Verified 2026-10-06
Content and calculation method last reviewed: