The 7 Best Solar Powered Calculators

By Kami Turky

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There are hundreds of solar-powered calculators available on the market and it can be hard to choose the best one or figure out which one is right for you. 

That’s why I’ve tested over 20 different solar calculators and rounded up the most impressive and useful models for you.

So without further ado, let’s dive into the best solar-powered calculators.

Best Solar-Powered Calculator Selections

Key Features

  • Dimensions: 4.8 x 5.75 x 2.01 inches
  • Weight: 5 ounces
  • Display: 12 digits
Helect Calculator, Standard Function Desktop Calculator, Black

Today’s first pick is the Helect Standard Function Solar Calculator – a great choice if you need a basic, easy-to-use desktop calculator. 

Helect compact 4.8 x 5.75 x 2.01 inches design and lightweight construction of only 5 ounces make it a perfect fit for any small desk, without ever being intrusive.

The 12-digit LCD display is easy to read, so you don’t have to struggle to convert currencies, calculate profit margins, and many more.

I actually purchased this calculator 3 years ago and I still use it in my to this day to help me with my finances – I never faced a situation where I needed a more advanced feature. 

It’s also dual powered as it uses both solar energy and an AA battery to store energy, so you can use it in any type of light condition.

You can rely only on the solar panel but I don’t recommend it, as the battery provides a more reliable source of power for those times when you don’t have access to light.

The only setback I have with this model is that the button holes are too large for most buttons, so they often stuck.

But overall, I still believe this would be the perfect solar-powered calculator if you’re looking for a simple, inexpensive, and reliable calculator.


  • Affordable price
  • Large 12-digit LCD display
  • Big and responsive buttons
  • Sleek and modern design


  • Button openings are too large

Key Features

  • Dimensions: 5.4 x 4 x 1.25 inches
  • Weight: 4.2 ounces
  • Display: 8 digits
Casio MS-80B Standard Function Desktop Calculator,Black 147D×103W×28.8H mm

Tax calculations can be a real hassle, but with the Casio MS-80B, you can tackle even the most complex calculations with ease. 

It has the same array of features our previous pick had in addition to the tax rate keys and independent memory keys, which makes figuring out taxes and converting currencies a breeze.

I used this model the last tax season – it saved me from all the potential mistakes that might occur from manual calculations.

The 8-digit LCD display has a reflective layer that reflects any light that strikes it, making it easier to read against any light – I never had to squint in order to view the numbers on the display.

But the versatility of this calculator really comes from the solar power source and a backup battery for when there’s not enough sunlight.

Even if it’s cloudy or dark, you can charge the battery with the office lamp and keep calculating without missing a beat. 

One problem I have with this model is that its buttons feel a bit hard to press, I wish they were a bit more responsive.

Despite this minor issue, I still consider this to be the best basic and portable solar tax calculator on the market.


  • Compact size and lightweight
  • Very clear antiglare display
  • Dual powered


  • Buttons are a bit hard to press

Key Features

  • Dimensions: ‎4.35 x 3.58 x 0.37 inches
  • Weight: ‎2.47 ounces
  • Display: 8 digits
Casio SL-100L Basic Solar Folding Compact Calculator, Multicolor

This time, Casio has crushed it with its folding solar calculator, giving us more convenience so we can carry it around without taking up much space.

The foldable design and its feather-light weight make it the size of your palm so you can simply slip it into your pocket or purse for on-the-go calculations.

I take this calculator every time I go out for any kind of shopping or lunch with my friends so I can easily split the bill and calculate the tip. 

The only downside is that the LCD display doesn’t reflect light, causing a distracting glare in some situations.

Despite these minor flaws, I still recommend this calculator for those who need a reliable, portable, and efficient solar folding calculator.


  • Modern and stylish folding design
  • Nice spacing between buttons
  • Dual powered


  • The LCD display isn’t antiglare

Key Features

  • Dimensions: ‎4.25 x 2.5 x 0.7 inches
  • Weight: 2.4 ounces
  • Display: 8 digits
Sharp Electronics 8-Digit Twin Powered Calculator (EL-243S/EL-243SB)

Sometimes, you just need a classic hand-held calculator for some quick calculations. 

That’s where the Sharp Electronics 8-Digit Calculator comes in, offering simple and precise calculations on the go. 

The calculator has an 8-digit display for all your number-crunching needs and an attached plastic hardcover to protect it from breaking and scratches.

This plastic cover is so durable that even after I’ve dropped it multiple times, it still works like a charm.

The memory plus, memory minus, and recall/clear memory keys have helped me every time I need to note down or recall some numbers.

The only catch is that I felt the keys were so small for my hand, making it a bit uncomfortable when pressing them.

However, I still highly recommend this calculator for those who are looking for a reliable and efficient hand-held solar calculator.


  • Attached plastic hardcover for protection
  • Dual powered
  • 3 memory keys for storing and recalling numbers


  • The keys are too small to press comfortably

Key Features

  • Dimensions: ‎5.5 x 4.9 x 4.6 inches
  • Weight: 5.9 ounces
  • Display: 12 digits
Calculator,12-Digit Solar Battery Basic Calculator,Solar Battery Dual Power with Large LCD Display Office Calculators (Silver)

If you ever need to do some serious calculations without breaking the bank, the EastPin 12 Digit Solar Office Calculator is your ideal option. 

This calculator actually is more than enough for you to manage your monthly expenses, create a budget for multiple projects, and other financial matters.

I also love how the addition of the anti-slip rubber feet makes the calculator stay in place while I’m typing away on it. 

The 1.5v AA battery backup along with the 1-year warranty gave me the peace of mind that I could count on this calculator for a long time to come.

One drawback I noticed was that the plastic frame seemed a bit wobbly, causing it to give off a cheap feeling.

But if you don’t mind carrying a slightly heavier device and need a reliable 12-digit solar office calculator, then the EastPin is definitely worth considering.


  • Large 12-digit display
  • Big buttons for easy pressing
  • 1.5v AA battery backup
  • Comes with a 1-year warranty


  • The plastic frame feels a bit cheap

Key Features

  • Dimensions: ‎2.9 x 0.6 x 5 inches
  • Weight: 4.6 ounces
  • Display: 10 digits

I swear Casio hasn’t paid me to say this, but the Casio FX 260 Solar II Scientific Calculator is just an absolute beast. 

It has 144 built-in math functions to help all math geeks out there to work with calculations from pre-algebra, and algebra 1 and 2, to trigonometry, and statistics.

I still rely on this model every time I face a crazy math problem, and it’s always been a lifesaver.

What I loved most is that the slide-on hardcover is so sturdy and thick that it has already survived several drops and spills without a single scratch.

The only issue I had with it was the 2.25-inch LCD display which was a bit too tiny for me and made me feel uncomfortable when trying to read the answers.

All in all, I’d still highly recommend the Casio FX 260 Solar II Scientific Calculator to anyone looking for a powerful and efficient device with advanced features.


  • 144 built-in math functions
  • Slide-on hardcover for protection
  • Responsive big keys
  • 2 AA backup included batteries


  • The LCD display is a bit too small for comfortable use

Key Features

  • Dimensions: ‎6.89 x 3.98 x 1.02 inches
  • Weight: 8.9 ounces
  • Display: 12 digits
Upgraded 991ES Plus Scientific Calculator, ROATEE Professional Scientific Calculators with Erasable LCD Writing Tablet, Solar and Battery Dual Power,Desktop Calculator with Notepad for Office, School

Last but not least, we have the Roatee Solar Professional Calculator for anyone who needs a professional-grade device to crunch numbers.

It features 417 computing functions to cover all your needs, such as complex numbers, vector and matrix calculations, programming functions, and more.

I used this calculator last year for my engineering diploma, and its wide functions were more than enough to tackle all the crazy equations I could throw at it. 

The biggest plus for me is that this calculator comes with a 4-line LCD display which makes it pretty convenient to read the answers without any strain. 

And the stylus pen made it easy for me to take notes while solving equations, and then with the press of a button, all my scribbles were wiped away.

The only issue I have with this calculator is its hefty price, which might be a bit too expensive for some.

But this calculator is totally worth every penny if you don’t mind shelling out for a professional-grade device.


  • 417 computing functions
  • High-quality shockproof material
  • Smooth, responsive keys
  • 4 Lithium Ion backup included batteries


  • Expensive price tag

How Do Solar Calculators Work?

Solar calculators work the same way as regular calculators.

The only difference is that they have a small solar panel on the front to absorb light energy, which is then converted into electrical energy and used to power the calculator’s internal components.

When there is excess energy, it is usually stored in a rechargeable battery which helps keep the calculator running even when there is no light.

Note: Some solar calculators don’t have rechargeable batteries – they rely on the solar panel as their primary energy source with the battery only acting as a back-up. Once this backup runs out, you will have to replace it to keep your calculator functioning.

How to Choose the Best Solar-Powered Calculator?

1. Features of the Calculator

Depending on what you need the calculator for, you should look into features such as the number of built-in functions.

If you just need a calculator for everyday calculations and basic operations, then a standard one should suffice such as our best desktop pick, Helect Solar Calculator.

However, if you’re an engineering or physics student, you need a calculator suitable for complex operations from basic algebra to calculus and differential equations such as Casio FX 260 model.

2. Display Size & Quality

Of course, no one likes to squint their eyes when trying to read the calculator’s display. 

This is why I made sure to pick models with an LCD display that’s large enough for comfortable use and offers the highest resolution.

Some calculators also might have an annoying glare as well, which can make using them even more difficult.

So I tested every solar calculator to make sure they have an antiglare coating and reflective layer to bounce off any intense light, with the best one being Helect Solar Calculator.

3. Solar Panel Size

The solar panel harnesses light and converts it into electrical energy to power the calculator. 

The larger the solar panel the more it can absorb light at once and reduce the need for light exposure.

When the solar panel is large enough, even the indirect light from fluorescent bulbs and LEDs can be used to power the calculator.

But if the solar panel isn’t efficient and large enough, then the calculator won’t generate enough energy and you will have to expose it to direct sunlight for extended periods of time.

4. Size of the Calculator

Some solar calculators are in the size of the purse for easy portability and some other are larger and more suitable for desktop use. 

If you’re looking for a calculator for quick calculations on the go, I recommend a foldable or pocket-sized one such as our pick Casio SL-100L

But if you need to crunch complex numbers and equations, then a larger device such as our pick Roatee Solar Professional Calculator would be the best choice.

What Are the Benefits of Solar-Powered Calculators?

The main benefit of solar-powered calculators is that they are convenient.

You don’t need to worry about replacing the batteries or charging them up. 

The solar panel absorbs enough energy from the sun and stores it in the battery so you don’t have to worry about running out of power.


Do Solar Panels on Calculators Actually Work?

Solar panels on the calculators do work, as long as they are exposed to enough light. 

How Long Do Solar-powered Calculators Last?

Solar-powered calculators last for several years, depending on the quality of the solar panel and battery.

Do Solar Calculators Work at Night?

Solar calculators work at night as they can use any artificial light as long as it’s powerful enough, such as LED lights. 

But if you don’t have a light source, you can still count on the rechargeable battery as most of them are dual powered.

How Do I Charge My Solar Calculator without Sunlight?

You can charge your solar calculator without sunlight by placing it under a bright artificial light.

Can You Change the Battery in a Solar-powered Calculator?

You can change the battery in a solar-powered calculator if it doesn’t work properly or if the battery is dead. 

However, the average battery life is about 3 years based on your usage, so you won’t need to replace it very often.

How Long Does It Take for Solar Calculators to Charge?

It can take about 20 hours of direct sunlight to fully charge a solar calculator.


Phew! Now that you know all about solar-powered calculators and how to choose the best one for your needs, you should be ready to make an informed decision.

And if you ask me, I’d say Roatee Solar Professional Calculator is the best option for its wide range of features, durable battery, and shockproof design. 

So go ahead and invest in one of these smart devices, and you’ll be set to crunch those numbers with ease! 

Kami Turky

Kami is a solar engineer with nearly a decade of experience in researching, testing, and reviewing various solar products.He has also provided technical consultation to several organizations on the best ways to incorporate solar energy into their operations.When he’s not busy helping others find the best solar solutions, Kami enjoys spending time outdoors, hiking, camping, and exploring the natural wonders of his home state.

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