A calculator can look like one of the simpler back-to-school purchases.
Then you search online: Scientific calculator. Advanced scientific calculator. Graphical calculator. Hundreds of functions. Solar power. Exam mode. Models with remarkably similar names and very different prices.
For parents, the obvious question is: Which one does my child actually need?
The answer depends much more on the course they are studying than on buying the calculator with the longest feature list.
For most GCSE students, a good scientific calculator is enough.
For A-Level Maths, an advanced scientific calculator may be a much better long-term choice.
And for some A-Level or Further Maths students, a graphical calculator can provide capabilities that justify the significantly higher price.
Here is how we would choose in 2026.
The quick answer
Student | Our recommendation | Typical current price* | Check latest prices on Amazon |
|---|---|---|---|
KS3 / most GCSE students | Casio fx-83GT CW+ | Around £14–£17 | |
KS3 / GCSE - solar option | Casio fx-85GT CW+ | Around £15–£19 | |
Higher GCSE / A-Level | Casio fx-991CW+ UK | Around £21–£36 | |
A-Level / Further Maths wanting graphing | Casio fx-CG100 | Around £108–£120 |
*Prices change frequently and promotions may reduce these figures. Check the current retailer price before buying.
First: check what the school recommends
This is more important than choosing between two calculators with slightly different specifications. Schools often standardise around particular models because teachers can then demonstrate the same key sequences to an entire class. That has a real learning benefit.
A calculator may be capable of doing everything a student needs, but if every demonstration in class uses a completely different menu system, the student has another interface to translate.
So before buying: Ask the maths department which model or range they recommend.
For exam use, students should also check the requirements of their qualification and examination centre.
The Joint Council for Qualifications (JCQ) does not publish one universal list of “approved calculators”. Instead, calculators must meet the relevant rules, and an awarding body can vary those rules for a particular qualification. JCQ also tells candidates to check with their teacher which calculator they may use.
That means a retailer saying “exam suitable” should never replace checking the actual course requirements.
Start with the course, not the calculator
Buying the most advanced calculator available is not automatically the best decision. A Year 8 student does not usually need a £100 graphical calculator. Equally, buying a very basic calculator for a student who is about to begin A-Level Maths may simply mean buying another one later.
A sensible progression looks something like this.
Calculator requirements increase from KS3 through GCSE and A-Level
Key Stage 3 and GCSE
Students typically need a reliable scientific calculator that handles:
fractions and decimals;
percentages;
powers and roots;
standard form;
trigonometry;
logarithms;
statistics;
tables of values; and
the normal range of GCSE mathematical calculations.
For this stage, the current Casio fx-83GT CW+ and fx-85GT CW+ both provide 290 functions and are designed around the UK curriculum. The main practical distinction is power: the fx-83GT CW+ is battery-powered, while the fx-85GT CW+ adds solar power with battery backup.
A-Level Maths
A-Level introduces calculations where a more capable scientific calculator becomes much more useful. An advanced model can help with areas such as:
equation solving;
statistics and distributions;
numerical calculations;
tables;
more advanced functions; and
the wider mathematical demands of post-16 study.
The current fx-991CW+ UK has more than 540 functions and is specifically positioned for Key Stages 3–5, including GCSE Further Maths and AS/A-Level Mathematics.
A-Level and Further Maths with graphing
A graphical calculator is a much larger investment. It can display functions visually, explore graphs, work with statistics and provide a more interactive way to investigate mathematical relationships.
Casio's current UK flagship is the fx-CG100, which replaced the fx-CG50. It includes a colour display, more than 3,000 functions and a dedicated UK Exam Mode.
It is impressive. It is also unnecessary for many students. Buy it because the course, school or learner will genuinely use the capability - not simply because it is the most expensive option.
Student using a scientific calculator alongside handwritten mathematical working
Our four recommendations
1. Casio fx-83GT CW+ - best straightforward choice for GCSE
Best for: KS3 and GCSE
Typical price: around £14–£17
Power: Battery
Functions: 290+
If you simply want a dependable calculator for secondary school and GCSE, this is the easiest recommendation.
The fx-83GT CW+ is part of Casio's new 2026 ClassWiz+ generation and replaces the previous fx-83GT CW.
The update includes easier menu shortcuts, quicker format conversion and functionality designed around UK and Irish curricula. Casio says it is permitted in GCSE and A-Level examinations where calculators are allowed.
What we like
suitable for the vast majority of GCSE requirements;
large textbook-style display;
familiar model family widely used in UK schools;
comparatively inexpensive;
no unnecessary complexity for younger students;
available in several colours.
What to consider
It is not the model we would buy specifically for a student starting A-Level Maths if you are happy to spend a little more now.
TutorTech verdict: Best value for most GCSE students.
Check the latest Casio fx-83GT CW+ prices on Amazon →
2. Casio fx-85GT CW+ - best GCSE choice if you want solar backup
Best for: KS3 and GCSE
Typical price: around £15–£19
Power: Solar + battery backup
Functions: 290+
Functionally, this is very close to the fx-83GT CW+.
The reason to spend the small amount extra is primarily the dual-power system.
It has the same core ClassWiz+ functionality but adds solar power with battery backup. Casio also says variants are made using up to 90% recycled materials, depending on model.
What we like
all the main advantages of the fx-83GT CW+;
solar power with battery backup;
sensible long-term everyday school calculator;
small price premium rather than a major upgrade cost.
What to consider
Do not expect dramatically more mathematical functionality than the fx-83GT CW+.
You are mainly paying for the power arrangement and construction differences.
TutorTech verdict: Our preferred everyday GCSE model if the small price difference is unimportant.
Check the latest Casio fx-85GT CW+ prices on Amazon →
3. Casio fx-991CW+ UK - best scientific calculator for A-Level
Best for: Higher GCSE, Further Maths and A-Level
Typical price: around £21–£36
Power: Solar + battery backup
Functions: 540+
For a student moving into A-Level Maths, this is where we would start looking.
The fx-991CW+ UK is the 2026 UK-specific replacement for the fx-991CW.
It retains the familiar ClassWiz approach but adds UK-specific functionality and more than 540 functions. Casio recommends it for GCSE Further Maths and AS/A-Level Maths, as well as earlier key stages.
What we like
much broader functionality than the entry-level models;
specifically configured for UK curriculum use;
useful statistical and equation-solving capabilities;
still relatively affordable compared with a graphical calculator;
a sensible model to buy once and use across GCSE into A-Level.
What to consider
For a Year 7 or Year 8 learner, much of the extra functionality may go unused.
More capability also means more menus and options to learn.
TutorTech verdict: Best all-round scientific choice for a student expecting to continue Maths beyond GCSE.
Check the latest Casio fx-991CW+ UK prices on Amazon →
4. Casio fx-CG100 - best graphical option for advanced maths
Best for: A-Level Maths, Further Maths and students who will genuinely use graphing
Typical price: around £108–£120
Power: Battery
Type: Graphical calculator
This is a completely different price category.
The fx-CG100 replaced Casio's popular fx-CG50 and is now its current advanced graphical calculator for UK students.
It offers a high-resolution colour display, graphing, statistics and more than 3,000 functions. It also has a dedicated UK Exam Mode designed to make the required exam setup easier to access.
What we like
graphing makes many mathematical relationships easier to explore visually;
powerful option for A-Level and Further Maths;
dedicated UK mode and easily accessible Exam Mode;
colour display;
USB-C connectivity outside examinations.
What to consider
The price. For many GCSE students - and plenty of A-Level students - it would be unnecessary.
It also requires the learner to become genuinely fluent with the device for the investment to make sense.
TutorTech verdict: Excellent for the right advanced student; excessive for everyone else.
Check the latest Casio fx-CG100 prices on Amazon →
Do you need to replace an older calculator?
Usually, no. A new model appearing does not automatically make the calculator already sitting in a school bag obsolete.
For example, Casio says the previous fx-991CW has been replaced commercially by the fx-991CW+ UK, but the older model remains suitable for its intended educational use.
If a student already knows their calculator well, it performs the functions they need, and it complies with the relevant examination requirements, familiarity can be more valuable than owning the latest model.
Don't create unnecessary expense for an upgrade.
Calculator rules in UK exams: what parents should know
This is the section we would pay most attention to.
JCQ's candidate guidance effective from 1 September 2026 says students should check with their teacher which calculator they may use. Where calculators are allowed, candidates must ensure the device works properly and follow the examination requirements around stored information and permitted functionality.
JCQ's calculator guidance prohibits capabilities such as:
symbolic algebra manipulation;
symbolic differentiation or integration;
language translation;
communication with other devices or the internet; and
accessing information stored beforehand during the exam.
Graphical calculators may be used where compliant, and an appropriate Exam Mode may disable prohibited functionality.
The safest rule is simple: Never assume. Ask the school or examination centre before the exam.
Do not wait until the exam to learn the calculator
This may be more important than the model itself. A calculator is only useful when the student knows how to use it.
Students should become comfortable with:
switching between exact and decimal forms;
entering fractions correctly;
using brackets;
standard form;
trigonometric settings;
statistics;
correcting an entry;
recognising when an answer is clearly unreasonable.
Learning unfamiliar calculator menus during an exam wastes time and increases the chance of mistakes. The best calculator is therefore not simply the one with the most functions.
It is the one with the right functions and familiar enough that the student can concentrate on the mathematics rather than the buttons.
Which one should you buy?
Our simple recommendation is:
For most GCSE students: Choose the Casio fx-83GT CW+.
For GCSE students who want solar power: Choose the Casio fx-85GT CW+.
For students moving towards A-Level Maths: Choose the Casio fx-991CW+ UK.
For A-Level/Further Maths students who specifically want graphical capability: Consider the Casio fx-CG100.
But check what the school teaches with before buying. A £15 calculator a student knows extremely well can be a much better educational tool than a £110 calculator they barely understand.
For more carefully selected study tools, see our TutorTech recommended Amazon resources:
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