How Many Solar Panels Do I Need? Calculator Shows Correct Sizing (Free)
So where to start when answering the question, how many solar panels do I need, is with the calculator of solar panel needs.
How To Calculate Solar Panel Needs
How to calculate solar panel needs requires the following information: How many hours of direct sunlight is available in the specific state on average every day?
The below table indicates the number of solar hours in the largest cities in every state:
| State | City | Solar Hours | kWh per 1kW |
| Alabama | City: Birmingham | 5.26 solar hours | 1,422 kWh per 1kW |
| City: Huntsville | 5.08 solar hours | 1,418 kWh per 1kW | |
| City: Mobile | 5.49 solar hours | 1,540 kWh per 1kW | |
| City: Montgomery | 5.43 solar hours | 1,513 kWh per 1kW | |
| Alaska | City: Anchorage | 3.40 solar hours | 1,053 kWh per 1kW |
| Arizona | City: Flagstaff | 6.21 solar hours | 1,695 kWh per 1kW |
| City: Phoenix | 6.52 solar hours | 1,753 kWh per 1kW | |
| City: Tucson | 6.54 solar hours | 1,807 kWh per 1kW | |
| City: Flagstaff | 6.21 solar hours | 1,695 kWh per 1kW | |
| City: Phoenix | 6.52 solar hours | 1,753 kWh per 1kW | |
| City: Tucson | 6.54 solar hours | 1,807 kWh per 1kW | |
| Arkansas | City: Little Rock | 3.40 solar hours | 1,401 kWh per 1kW |
| California | City: Bakersfield | 6.16 solar hours | 1,714 kWh per 1kW |
| City: Fresno | 5.96 solar hours | 1,636 kWh per 1kW | |
| City: Los Angeles | 6.13 solar hours | 1,708 kWh per 1kW | |
| City: Modesto | 5.96 solar hours | 1,652 kWh per 1kW | |
| City: Oakland | 5.62 solar hours | 1,598 kWh per 1kW | |
| City: Oxnard | 6.04 solar hours | 1,702 kWh per 1kW | |
| City: Riverside | 6.28 solar hours | 1,790 kWh per 1kW | |
| City: Sacramento | 5.83 solar hours | 1,620 kWh per 1kW | |
| City: Salinas | 5.61 solar hours | 1,598 kWh per 1kW | |
| City: San Bernardino | 6.20 solar hours | 1,714 kWh per 1kW | |
| City: San Diego | 5.70 solar hours | 1,627 kWh per 1kW | |
| City: San Francisco | 5.56 solar hours | 1,593 kWh per 1kW | |
| City: San Jose | 5.86 solar hours | 1,667 kWh per 1kW | |
| Colorado | City: Colorado Springs | 5.72 solar hours | 1,614 kWh per 1kW |
| City: Denver | 5.69 solar hours | 1,59 kWh per 1kW | |
| City: Fort Collins | 5.19 solar hours | 1,455 kWh per 1kW | |
| Connecticut | City: Bridgeport | 4.63 solar hours | 1,307 kWh per 1kW |
| City: Hartford | 4.68 solar hours | 1,273 kWh per 1kW | |
| Florida | City: Fort Lauderdale | 5.74 solar hours | 1,662 kWh per 1kW |
| City: Jacksonville | 5.52 solar hours | 1,478 kWh per 1kW | |
| City: Miami | 5.77 solar hours | 1,623 kWh per 1kW | |
| City: Orlando | 5.64 solar hours | 1,570 kWh per 1kW | |
| City: Tallahassee | 5.41 solar hours | 1,446 kWh per 1kW | |
| City: Tampa | 5.76 solar hours | 1,610 kWh per 1kW | |
| Georgia | City: Atlanta | 5.26 solar hours | 1,470 kWh per 1kW |
| City: Savannah | 5.34 solar hours | 1,459 kWh per 1kW | |
| Hawaii | City: Honolulu | 5.87 solar hours | 1,683 kWh per 1kW |
| State | City | Solar Hours | kWh per 1kW |
| Idaho | City: Boise | 5.17 solar hours | 1,439 kWh per 1kW |
| Illinois | City: Chicago | 4.55 solar hours | 1,307 kWh per 1kW |
| City: Springfield | 4.62 solar hours | 1,331 kWh per 1kW | |
| Indiana | City: Fort Wayne | 4.61 solar hours | 1,317 kWh per 1kW |
| City: Indianapolis | 4.72 solar hours | 1,342 kWh per 1kW | |
| Iowa | City: Des Moines | 4.79 solar hours | 1,362 kWh per 1kW |
| Kansas | City: Kansas | 5.04 solar hours | 1,464 kWh per 1kW |
| Maryland | City: Baltimore | 4.83 solar hours | 1,437 kWh per 1kW |
| Massachusetts | City: Boston | 4.72 solar hours | 1,339 kWh per 1kW |
| City: Springfield | 4.88 solar hours | 1,391 kWh per 1kW | |
| Michigan | City: Detroit | 4.60 solar hours | 1,325 kWh per 1kW |
| City: Grand Rapids | 4.48 solar hours | 1,280 kWh per 1kW | |
| Minnesota | City: Duluth | 4.37 solar hours | 1,278 kWh per 1kW |
| City: Mpls/St Paul | 4.62 solar hours | 1,320 kWh per 1kW | |
| Mississippi | City: Jackson | 4.47 solar hours | 1,277 kWh per 1kW |
| State | City | Solar Hours | kWh per 1kW |
| Missouri | City: Kansas | 5.04 solar hours | 1,414 kWh per 1kW |
| City: Springfield | 5.16 solar hours | 1,412 kWh per 1kW | |
| City: St. Louis | 4.99 solar hours | 1,387 kWh per 1kW | |
| Nebraska | City: Lincoln | 5.02 solar hours | 1,436 kWh per 1kW |
| City: Omaha | 5.02 solar hours | 1,425 kWh per 1kW | |
| Nevada | City: Las Vegas | 6.37 solar hours | 1,764 kWh per 1kW |
| City: Reno | 5.99 solar hours | 1,697 kWh per 1kW | |
| New Hampshire | City: Concord | 4.83 solar hours | 1,303 kWh per 1kW |
| New Jersey | City: Newark | 4.74 solar hours | 1,313 kWh per 1kW |
| New Mexico | City: Albuquerque | 6.41 solar hours | 1,805 kWh per 1kW |
| New York | City: Buffalo | 4.34 solar hours | 1,221 kWh per 1kW |
| City: New York City | 4.58 solar hours | 1,310 kWh per 1kW | |
| City: Syracuse | 4.21 solar hours | 1,159 kWh per 1kW | |
| North Carolina | City: Charlotte | 5.18 solar hours | 1,419 kWh per 1kW |
| City: Wilmington | 5.29 solar hours | 1,493 kWh per 1kW | |
| North Dakota | City: Bismark | 4.72 solar hours | 1,364 kWh per 1kW |
| Ohio | City: Cincinnati | 4.68 solar hours | 1,301 kWh per 1kW |
| City: Cleveland | 4.68 solar hours | 1,290 kWh per 1kW | |
| City: Columbus | 4.57 solar hours | 1,296 kWh per 1kW | |
| City: Dayton | 4.70 solar hours | 1,330 kWh per 1kW | |
| City: Toledo | 4.62 solar hours | 1,326 kWh per 1kW |
| State | City | Solar Hours | kWh per 1kW |
| Oklahoma | City: Oklahoma | 5.54 solar hours | 1,579 kWh per 1kW |
| Oregon | City: Portland | 4.09 solar hours | 1,118 kWh per 1kW |
| Pennsylvania | City: Philadelphia | 4.78 solar hours | 1,334 kWh per 1kW |
| City: Pittsburgh | 4.46 solar hours | 1,210 kWh per 1kW | |
| Rhode Island | City: Providence | 4.74 solar hours | 1,334 kWh per 1kW |
| South Carolina | City: Charleston | 5.38 solar hours | 1,489 kWh per 1kW |
| South Dakota | City: Sioux Falls | 4.88 solar hours | 1,441 kWh per 1kW |
| Tennessee | City: Clarksville | 4.48 solar hours | 1,394 kWh per 1kW |
| City: Knoxville | 5.00 solar hours | 1,397 kWh per 1kW | |
| City: Memphis | 5.18 solar hours | 1,470 kWh per 1kW | |
| City: Murfreesboro | 4.97 solar hours | 1,404 kWh per 1kW | |
| City: Nashville | 4.91 solar hours | 1,390 kWh per 1kW | |
| Texas | City: Amarillo | 6.08 solar hours | 1.735 kWh per 1kW |
| City: Dallas | 5.50 solar hours | 1.552 kWh per 1kW | |
| City: Houston | 5.33 solar hours | 1.476 kWh per 1kW | |
| City: San Antonio | 5.54 solar hours | 1.545 kWh per 1kW | |
| Utah | City: Salt Lake | 5.32 solar hours | 1,554 kWh per 1kW |
| Vermont | City: Montpelier | 4.30 solar hours | 1,219 kWh per 1kW |
| Virginia | City: Richmond | 5.06 solar hours | 1,360 kWh per 1kW |
| Washington | City: Seattle | 3.97 solar hours | 1,157 kWh per 1kW |
| City: Spokane | 4.38 solar hours | 1,228 kWh per 1kW |
Entering the solar hours per day into an online solar panel calculator and adding the annual kWh consumed at the premises divided by kWh per 1kW (as indicated in the table), will determine the size of the solar system required. 9
Read About : Carbon Footprint: Solar Panel Manufacturing In 1 Simple Explanation
How Many kW Hours Does a Solar Panel Produce?
The next question in determining the answer to the question, how many solar panels do I need, is calculating the kW per solar panel.
The majority of solar panels are capable of producing up to 400 watts of power. The real-life output does however depend on direct sunlight, positioning and shading. 10
In general, a solar power array consisting of 30 solar panels would be more than sufficient to power a residential home.
The below table indicates the minimal, maximum, and average electricity output of popular solar panel brands (in Watts):
| Solar Panel Manufacturer | Minimum Output | Maximum Output | Average Output |
| Amerisolar | 240 W (Output) | 330 W (Output) | 285 W (Output) |
| Astronergy | 350 W (Output) | 370 W (Output) | 360 W (Output) |
| Axitec | 250 W (Output) | 385 W (Output) | 302 W (Output) |
| BenQ Solar (AUO) | 250 W (Output) | 295 W (Output) | 277 W (Output) |
| Boviet Solar | 320 W (Output) | 340 W (Output) | 330 W (Output) |
| Solar Panel Manufacturer | Minimum Output | Maximum Output | Average Output |
| Canadian Solar | 225 W (Output) | 410 W (Output) | 320 W (Output) |
| CentroSolar | 250 W (Output) | 320 W (Output) | 278 W (Output) |
| CertainTeed Solar | 70 W (Output) | 400 W (Output) | 308 W (Output) |
| ET Solar | 255 W (Output) | 370 W (Output) | 306 W (Output) |
| First Solar | 420 W (Output) | 460 W (Output) | 440 W (Output) |
| Solar Panel Manufacturer | Minimum Output | Maximum Output | Average Output |
| GCL | 310 W (Output) | 330 W (Output) | 320 W (Output) |
| Grape Solar | 160 W (Output) | 285 W (Output) | 237 W (Output) |
| Green Brilliance | 230 W (Output) | 300 W (Output) | 266 W (Output) |
| Hansol | 250 W (Output) | 360 W (Output) | 304 W (Output) |
| Hanwha | 365 W (Output) | 385 W (Output) | 375 W (Output) |
| Solar Panel Manufacturer | Minimum Output | Maximum Output | Average Output |
| Heliene | 250 W (Output) | 370 W (Output) | 306 W (Output) |
| JA Solar | 260 W (Output) | 410 W (Output) | 329 W (Output) |
| JinkoSolar | 315 W (Output) | 410 W (Output) | 367 W (Output) |
| Kyocera | 260 W (Output) | 330 W (Output) | 295 W (Output) |
| LG | 315 W (Output) | 415 W (Output) | 365 W (Output) |
| Solar Panel Manufacturer | Minimum Output | Maximum Output | Average Output |
| LONGi | 305 W (Output) | 455 W (Output) | 387 W (Output) |
| Mission Solar Energy | 300 W (Output) | 390 W (Output) | 334 W (Output) |
| Mitsubishi Electric | 270 W (Output) | 280 W (Output) | 275 W (Output) |
| Neo Solar Power | 310 W (Output) | 330 W (Output) | 320 W (Output) |
| Panasonic | 320 W (Output) | 370 W (Output) | 340 W (Output) |
| Solar Panel Manufacturer | Minimum Output | Maximum Output | Average Output |
| Peimar | 310 W (Output) | 310 W (Output) | 310 W (Output) |
| Peimar Group | 270 W (Output) | 330 W (Output) | 301 W (Output) |
| Phono Solar | 260 W (Output) | 350 W (Output) | 294 W (Output) |
| QCELLS | 285 W (Output) | 430 W (Output) | 358 W (Output) |
| REC | 275 W (Output) | 450 W (Output) | 347 W (Output) |
| Solar Panel Manufacturer | Minimum Output | Maximum Output | Average Output |
| RECOM | 265 W (Output) | 370 W (Output) | 308 W (Output) |
| Recom Solar | 310 W (Output) | 350 W (Output) | 330 W (Output) |
| ReneSola | 245 W (Output) | 320 W (Output) | 277 W (Output) |
| Renogy Solar | 250 W (Output) | 300 W (Output) | 268 W (Output) |
| RGS Energy | 55 W (Output) | 60 W (Output) | 58 W (Output) |
| Solar Panel Manufacturer | Minimum Output | Maximum Output | Average Output |
| Risen | 270 W (Output) | 390 W (Output) | 329 W (Output) |
| S-Energy | 255 W (Output) | 385 W (Output) | 334 W (Output) |
| Seraphim | 255 W (Output) | 340 W (Output) | 294 W (Output) |
| Silfab | 300 W (Output) | 390 W (Output) | 335 W (Output) |
| Solaria | 350 W (Output) | 430 W (Output) | 375 W (Output) |
| Solar Panel Manufacturer | Minimum Output | Maximum Output | Average Output |
| Solartech Universal | 310 W (Output) | 325 W (Output) | 318 W (Output) |
| SunPower | 320 W (Output) | 435 W (Output) | 355 W (Output) |
| SunSpark Technology | 310 W (Output) | 310 W (Output) | 310 W (Output) |
| Talesun | 275 W (Output) | 415 W (Output) | 365 W (Output) |
| Talesun Solar Co. | 400 W (Output) | 400 W (Output) | 400 W (Output) |
Solar Panel Manufacturer Minimum Output Maximum Output Average Output Trina 265 W (Output) 415 W (Output) 337 W (Output) Trina Solar Energy 260 W (Output) 320 W (Output) 288 W (Output) Upsolar 270 W (Output) 365 W (Output) 311 W (Output) Vikram Solar 320 W (Output) 340 W (Output) 330 W (Output) Winaico 325 W (Output) 340 W (Output) 332 W (Output)
Solar Power Calculation Formula
Calculating the energy produced by a solar panel can be done by implementing the following solar power calculation formula: 11
5 hours of direct sunlight x 290 watts (premium panel wattage) = 1,450 wh or 1.5 kWh.
This means that the total output of a single solar panel would be around 550 kWh every year.
Solar Panels kWh Calculator
A solar panel kWh calculator takes into account the solar cell efficiency as well as the size of the solar panel.
When calculating the kWh of an entire solar panel array, the above example can be employed:
5 hours of direct sunlight 30 solar panels on the roof (290 W each) = 8.7 kW system.
If the 5 solar hours are multiplied by 8.7 kW, it equals 43.5 kWh of electricity production per day.
Furthermore, if 43.5 is multiplied by 365 days, it equals 15,800 kWh of electricity production per year.
This should be more than sufficient for a residential home, as the average electrical energy consumption per household in the US is around 10,600 kWh. 2
kWh Per Day Solar System
A 60 kWh per day solar system (6 kW system) is one of the most common solar systems in the US. 12 A 60 kWh per day solar system is capable of producing up to 900 kWh per month. This is sufficient for many households, considering that the average US household consumes around 893 kWh of electricity every month.
However, it may not be a one-size-fits-all solution, because different households consume electricity in different ways.
Among the renewable energy sources, solar has the least amount of carbon emissions produced. Regardless, everyone has a personal carbon ecological footprint and can measure it using a calculator.
How Many Solar Panels For 60 kWh Per Day?
A common question about a 60 kWh per day solar system is, how many solar panels for 60 kWh per day?
A 6 kW system requires on average between 16 and 18 solar panels, depending on the watt output per panel. 3
kWh Per Day Solar System
A 70 kWh per day solar system with 275 – 320 W solar panel output will require between 25-28 solar panels.
In general, a single solar panel measures 1.7m2, which means the roof area required is around 48m2.
How Many Solar Panels Do I Need?
Tying in with the question, how many solar panels do I need, is the common question, how many solar panels to power a house?
The answer depends on energy usage, solar hours, and the brand of solar panels.
How Many Solar Panels To Power A House?
Existing electricity usage should be calculated by combining a full year’s consumption and dividing it by 12.
Daily peak sun hours per month is determined by multiplying the particular state’s solar hours by 30. If the state receives 150 solar hours, 1 kW of solar will be sufficient to produce 150 kWh of electricity each month.
Monthly electricity consumption should then be divided by the solar hours to find the exact solar system size required in kW.
The example is as follows:
893 kWh consumed energy / 135 monthly solar hours = 6.61 kW of solar power
How Many Solar Panels Do I Need For A 4-Bedroom House?
The next question then is, how many solar panels do I need for a 4-bedroom house?
Once the size of the required solar system is determined, the size can be multiplied by 1,000 to convert the size from kW to W. 14
The same example: 6.61 kW solar x 1,000 = 6,610 W of solar
Then the system size (in watts) can be divided by the watts of the solar panels. (The average US solar panel is 370 W.
6,610 W solar / 370 W panel = 18 panels
An average 4-bedroom house in the US would require a 7.75 kW solar array, consisting of 375 W panels. The number of panels would be around 21. 4
The below table indicates the number of panels required per typical bedroom size:
| Number of bedrooms | Average system size | Number of panels (375W) | Number of panels (315W) |
| 1 bedroom | 1.94 kW | 6 panels | 7 panels |
| 2 bedrooms | 3.88 kW | 11 panels | 13 panels |
| 3 bedrooms | 5.82 kW | 16 panels | 19 panels |
| 4 bedrooms | 7.75 kW | 21 panels | 25 panels |
| 5 bedrooms | 9.69 kW | 26 panels | 31 panels |
| 6 bedrooms | 11.63 kW | 32 panels | 37 panels |
Solar Panel Sizing Calculator
A solar panel sizing calculator requires the following inputs:
- User load
- Battery type configuration
- Chosen solar array configuration
- Type of solar panels
- Inverter type
- Feedback should then be tweaked according to personal requirements 5
How Many Solar Panels Do I Need For 400 kWh Per Month?
How many solar panels do I need for 400 kWh per month: 15
How Many Solar Panels Do I Need For 500 kWh Per Month?
How many solar panels do I need for 500 kWh per month:
How Many Solar Panels Do I Need For 700 kWh Per Month?
How many solar panels do I need for 700 kWh per month:
How Many Solar Panels Do I Need For 1500 kWh Per Month?
How many solar panels do I need for 1500 kWh per month:
How Many Solar Panels Do I Need For 3000 kWh Per Month?
How many solar panels do I need for 3000 kWh per month:
How Many Solar Panels Do I Need For 4,000 kWh Per Month?
How many solar panels do I need for 4,000 kWh per month:
How Many Solar Panels Do I Need For 5000 kWh Per Month?
How many solar panels do I need for 5000 kWh per month:
How Many Solar Panels Do I Need Calculator?
How many solar panels do I need calculator: 16
- Energy consumption in kWh per year
- Solar hours per day
- Bill offset in percentage
- Environmental factor in percentage
- Solar system size (estimated)
- Required roof area (in m2)
- Number of panels required
- Required area in m2 7
Using the above information and solar calculators will provide a definite answer to the question, how many solar panels do I need?
How Much is the Average Per Month Solar System Cost of a Residential Solar Array?
The average cost of a residential solar array is around 2.94 per W.
How Much Kw Solar Panel Required For Home?
An average household in the US that consumes 1000 kWh would require 26-30 panels of 320 W each.
How Many Solar Panels Do I Need?
Calculating the required number of solar panels is dependent on the following calculation: Household hourly consumption x solar hours by area divided by the panel wattage.
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References
1 Coastal Solar. (2022, August 9). Find How Many Solar Panels You’ll Need – In 8 Easy Steps. Coastal Solar. Retrieved November 20, 2022 from
2 Aggarwal, V. (2022, November 1). What is the Output of a Solar Panel? | EnergySage. EnergySage Blog. Retrieved November 20, 2022 from
3 guide, s. (2021, December 28). How Much Electricity Does a Solar Panel Produce? SolarReviews. Retrieved November 20, 2022 from
4 SolarReviews. (2022, August 19). How Many Solar Panels Do I Need? | Solar Calculator. SolarReviews. Retrieved November 20, 2022 from
5 TheSunPays. (n.d.). Solar System Sizing Tool Calculator – TheSunPays. TheSunPays. Retrieved November 20, 2022 from
6 Unbound Solar. (2019, November 26). How many solar panels do I need to power my home? Unbound Solar. Retrieved November 20, 2022 from
7 Raman, M., Darcy, M. (2022, November 4). Solar Panel Calculator. Omni Calculator. Retrieved November 20, 2022 from
8 Office of ENERGY EFFICIENCY RENEWABLE ENERGY. (2022). Solar Rooftop Potential. Department of Energy. Retrieved November 20, 2022, from
9 Tennessee Valley Authority. (2022). Tennessee Valley Solar Calculator. Tennessee Valley Authority. Retrieved November 20, 2022, from
10 Government of India. (2022). Ministry of New and Renewable Energy. National Portal for Rooftop Solar. Retrieved November 20, 2022, from
11 ESRL Global Monitoring Laboratory. (2022). NOAA Solar Calculator. ESRL Global Monitoring Laboratory. Retrieved November 20, 2022, from
12 NREL PVWatts Calculator. (2022). Solar Resource Data. PVWatts Calculator. Retrieved November 20, 2022, from
13 United States Government. (2022, August 31). Deciding Whether to Install Solar Panels on Your Home? A New NIST Web Tool Can Help. National Institute of Standards and Technology. Retrieved November 20, 2022, from
14 Gov.uk. (2022). Solar photovoltaic (PV) cost data. GOV.UK. Retrieved November 20, 2022, from
15 Government of India. (2022). Schemes. MNRE. Retrieved November 20, 2022, from
16 United States Government. (2022). Solar Power for Your Home. Federal Trade Commission | Consumer Advice. Retrieved November 20, 2022, from