Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more

At an assumed constant 100 watts, running a computer around the clock uses 2.4 kWh a day, 72 kWh in a 30-day month, and 876 kWh in a 365-day year. To estimate the energy-charge cost, multiply those units by the applicable rate on your electricity bill. At ₹4.50 per kWh, for example, 72 kWh costs ₹324 in energy charges—not necessarily ₹324 added to the complete bill.

How much electricity does a 100 W load use?

Convert watts to kilowatts by dividing by 1,000: 100 W ÷ 1,000 = 0.1 kW. Multiply by the hours the load runs:

Period Calculation Energy used
One day 0.1 kW × 24 hours 2.4 kWh
30-day month 2.4 kWh × 30 72 kWh
365-day year 2.4 kWh × 365 876 kWh

These are arithmetic totals for a constant 100 W load. They are not a measurement of OBS or of a particular computer: actual draw varies with the computer, workload, peripherals, and settings. Count a monitor, capture device, router, or other equipment only if its consumption is included in the 100 W figure.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

Estimate the cost using your electricity rate

Multiply energy use in kWh by the applicable energy charge in rupees per kWh. If R is your applicable rate, the estimates are:

#1 Best Overall
Watt Meter Power Meter Plug Home Electricity Usage Monitor 7 Modes Display
  • Various Monitoring Parameters: The power meter plug can monitor the power (W), energy (kWh), volts, amps, hertz, power factor, cost, minimum and maximum power (W), cumulative days and time of your appliances. By switching 7 display modes, you can easily know the various parameters while the appliance is working. The home energy monitor can also calculate and display how much power your appliance uses and how much electricity bill it cost in cumulative time
  • Upgraded LCD Display: With large screen size 2.36 inch x 1.85 inch, clearer monitor backlit, our electrical usage monitor can display the data clearer and more visible no matter day or night. 180°full wide viewing angles is great for reading and recording the data in any angles. No need to stand on the front of the display and bend over to read the numbers
  • Adjustable Backlight Time: Our upgraded watt meter has 5 options of backlight time. The default backlight time duration is 10 minutes(bL-0). If you want to change the backlight time, you can press and hold "UP" and "DOWN" button at the same time to enter backlight time setting, then press "UP" and "DOWN" to select the backlight time (bL-0 =10 minutes, bL-1=1 hour, bL-2=4 hours, bL-3=8 hours, bL-4=always on), finally press the "COST" to save the backlight time settings
  • Overload protection: When the power of the appliance exceeds the overload power, the LCD will display “OVERLOAD” to warn the user. All the buttons will quit working and can only be workable when you lower or remove the load power. The default overload power is 3680W and is adjustable from 0 to 3680W. In general, you need to set the overload power to 1800W before using. Just press the "function" button for more than 3 seconds to enter the setting
  • Data Memory Function: The wattage meter will record your power consumption data when you remove it from socket, or remove appliances from the electricity monitor. You can directly see the last data when you use it next time. This function can also automatically save the data when there is a sudden power failure
  • Daily energy charge: 2.4 × R
  • 30-day energy charge: 72 × R
  • Annual energy charge: 876 × R

For example, at ₹4.50/kWh, the 30-day calculation is 72 × ₹4.50 = ₹324 in energy charges. The ₹4.50 rate is an example from one Chhattisgarh domestic tariff slab, not a rate for all Indian households.

Why the amount varies across India

India has no single domestic electricity rate that applies to every household. The Ministry of Power says retail tariffs are determined by the appropriate electricity regulatory commissions, and state governments may provide subsidies (Ministry of Power, Government of India). Use your latest bill and the tariff order for your state or territory, matching your consumer category and consumption slab.

Rank #2
Upgraded Watt Meter Power Meter Plug Home Energy Monitor 8 Display Modes
  • Multi-function power monitor: Our electric usage monitor can monitor the power (W), electricity(kWh), voltage(V), frequency(Hz), current(A), power factor(PF), unit price($/kWh), total cost($) of your appliances. By switching 8 display modes, you can easily know the various parameters while the appliance is working. The “electricity” mode can calculate and display how much power your appliance uses. And the “total cost” mode will show how much electricity bill it cost in cumulative time
  • Overload protection: When the loading power of the appliance is over the default overload threshold 1800W, the whole display with backlight and the word “OVERLOAD” will keep flashing to warn the users. Please turn off the appliance for safety concern
  • Premium Material: The whole body of our energy meter is made of high-quality ABS material. It makes our home electricity usage monitor more long lasting, fireproof and anti-drop. The standard US socket and plug is suitable for all US standard appliances
  • Backlight Display: With white backlight and black words, the LCD display of our home power monitor can display the data clearer and help you to read the data easier no matter day or night. The backlight will only lights up when the device is connected to AC power. If no button is pressed, the backlight turns off automatically after 10 minutes. You can also press the "UP" button to turn off the backlight manually, and press any button to turn on backlight again
  • Easy to reset: No reset tool needed, our appliance power usage meter is easy to reset. You can press the “M” button for 5 seconds directly to reset the device. After reset, all cumulative data (electricity quantity, cost) will be cleared, and all settings will be restored to factory settings

These official schedules illustrate the variation; they are dated FY 2026–27 examples, not interchangeable prices:

Free tools Windows power users keep installed

One-click scans. No signup required.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.
Jurisdiction and schedule Domestic energy-charge slabs Other charges
Chhattisgarh State Electricity Regulatory Commission, FY 2026–27 ₹4.50/kWh for 101–200 units; ₹6.00 for 201–400; ₹7.00 for 401–600; ₹8.80 for 601 and above Separate fixed monthly charges; the schedule says fixed charges apply whether or not energy is consumed. CSERC
Department of Electricity, Lakshadweep, FY 2026–27 normal domestic schedule ₹3.55/kWh for 0–100 units; ₹5.30 for 101–200; ₹7.70 for 201–300; ₹10.05 for 301–400; ₹13.05 above 400 Fixed charges listed separately. Department of Electricity, Lakshadweep

Do not automatically apply the rate for your highest slab to all 72 additional units. Where billing is telescopic, added consumption can be charged across successive slabs; the marginal cost also depends on the household’s existing use and the precise tariff rules. The CSERC schedule describes its billing as telescopic.

Rank #3
Emporia Vue 3 Home Energy Monitor - Smart Home Automation Module and Real Time Electricity Usage Monitor, Power Consumption Meter, Solar and Net Metering for UL Certified Safe Energy Monitoring
  • SAFETY YOU CAN TRUST WITH UL CERTIFICATION: With Emporia Energy, your home energy monitoring is safe, reliable, and certified. The Emporia Vue is UL Listed, meaning it has met rigorous safety standards for electrical products in the U.S. and Canada. This certification ensures that every component has been thoroughly tested to prevent hazards, such as overheating, short-circuiting, or fire, offering you peace of mind as you manage your home’s energy consumption.
  • INSTALLS IN CIRCUIT PANEL of most homes with clamp-on sensors. Supports Single phase, Single-split phase, and 2-wire systems. 3-wire systems; 3-phase, 4-wire Wye systems with earthed (TN or TT) neutral (no-Delta) are supported with an additional 200A sensor (sold separately).
  • 24/7 ENERGY MANAGEMENT AND MONITORING: Automate, manage and control your home's real power anywhere, anytime to prevent costly repairs, conserve energy, and save costs. Monitor solar / net metering. PROTECTED BY A 1-YEAR WARRANTY.
  • LOWER YOUR ELECTRIC BILL: Configure settings in the Emporia Energy App to automate energy management for time of use, peak demand, excess solar, and rewards programs. You can even see live reporting and invaluable savings opportunities instantly. Gauge real-time spending and get actionable notifications and automated energy management to help you reduce costs.
  • REAL-TIME ENERGY DATA: REQUIRES 2.4 GHz WIFI WITH AN INTERNET CONNECTION to monitor energy use with iPhone / Android / Web app. Vue sensors collect energy data and are accurate from ±2%. The Vue is UL and CE Listed for your safety. 1 second data is only available in the app (when actively open) and retained 3 hours. Minute and hour data are retained in the cloud. 1 minute data is retained 7 days, 1 hour data is retained indefinitely. Export cloud data whenever you want in the app.

The calculation above covers energy charges only. Your total bill can also reflect fixed charges, duties, adjustments, and subsidies, so its change may not equal the energy-charge estimate.

Check the actual power draw

The 100 W assumption is useful for estimating a scenario, but it may not match your setup. If you need a more accurate figure, measure consumption at the wall, including only the devices you intend to count. For fluctuating power use, take measurements over a representative period and divide the energy used by that period to find average power; this follows U.S. Department of Energy guidance (DOE guidance on estimating energy use).

Rank #4
2 Pack Upgraded Watt Meter Power Meter Plug 7 Modes Display
  • Various Monitoring Parameters: The power meter plug can monitor the power (W), energy (kWh), volts, amps, hertz, power factor, cost, minimum and maximum power (W), cumulative days and time of your appliances. By switching 7 display modes, you can easily know the various parameters while the appliance is working. The home energy monitor can also calculate and display how much power your appliance uses and how much electricity bill it cost in cumulative time
  • Upgraded LCD display: With large screen size 2.36 inch x 1.85 inch, clearer monitor backlit, our electrical usage monitor can display the data clearer and more visible no matter day or night. 180°full wide viewing angles is great for reading and recording the data in any angles. No need to stand on the front of the display and bend over to read the numbers
  • Adjustable Backlight Time: Our upgraded watt meter has 5 options of backlight time. The default backlight time duration is 10 minutes(bL-0). If you want to change the backlight time, you can press and hold "UP" and "DOWN" button at the same time to enter backlight time setting, then press "UP" and "DOWN" to select the backlight time (bL-0 =10 minutes, bL-1=1 hour, bL-2=4 hours, bL-3=8 hours, bL-4=always on), finally press the "COST" to save the backlight time settings
  • Overload protection: When the power of the appliance exceeds the overload power, the LCD will display “OVERLOAD” to warn the user. All the buttons will quit working and can only be workable when you lower or remove the load power. The default overload power is 3680W and is adjustable from 0 to 3680W. In general, you need to set the overload power to 1800W before using. Just press the "function" button for more than 3 seconds to enter the setting
  • Data Memory Function: The wattage meter will record your power consumption data when you remove it from socket, or remove appliances from the electricity monitor. You can directly see the last data when you use it next time. This function can also automatically save the data when there is a sudden power failure
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Support on Ko-Fi

Or let it run in the cloud

If your goal is to keep a pre-recorded YouTube stream running, StreamNeo is an alternative to keeping a computer and OBS on at home. Upload a recording or build a playlist, add your YouTube stream key once, and go live; StreamNeo loops the uploaded video from the cloud.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.
  • Nothing has to stay on at home: the stream runs in the cloud.
  • Each slot streams your upload as made, up to 4K 60fps, at one flat price per slot.
  • Automatic recovery is included if YouTube drops the stream.
  • The first day is free with no card; one free day is available per account.

StreamNeo’s monthly option is $9.99 per month. See StreamNeo, or start your free day.

Best Value
Sale
HBN Watt Meter Plug with Backlight, Plug-in Socket Power Meter Electricity Usage Monitor Consumption Home Electrical Energy Monitor, Voltage Amps Wattage Electricity Usage Tester, 9 Display Modes
  • ✓ Backlit LCD Display: The watt meter features an upgraded backlit LCD display with a 160° wide viewing angle, providing clear and distinct data readings from any angle, day or night. (Note: To conserve energy, the backlight will automatically turn off after 15 seconds of continuous use.)
  • ✓ 9 Types of Data Display: This energy meter plug accurately monitors a wide range of electrical parameters, including power (W), apparent power (VA), energy consumption (kWh), usage time (hours), power frequency (Hz), power factor (PF), voltage (V), current (A), and electricity cost. The user-friendly interface allows you to easily read and navigate through 9 types of data with a single button.
  • ✓ Save Money and Energy: By toggling through the 9 display modes, you can gain insights into various operational parameters of your devices. The home energy monitor also calculates and displays the electricity consumption and cost over time, helping you save on your electricity bills by monitoring and managing energy usage.
  • ✓ Data Storage: The plug-in electricity meter stores all non-real-time data, ensuring no information is lost in the event of a sudden power outage. If data exceeds the screen’s maximum display range, the screen will flash as a reminder. Pressing and holding the reset button for 3 seconds will reset the cumulative data to zero.
  • ✓ Safe to Use: Rated voltage 125VAC, 60Hz, 15A maximum 1875W resistor and tungsten wire, 1/2HP. Clean and tidy interface, very simple to use.

Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.