Can you use a calculator on the TEAS? Yes, the built-in one: how to use it well
Yes. The ATI TEAS has a basic calculator built into the exam screen, and it is available in every section, at a test center and at home. You may not bring your own calculator, and a phone or smartwatch is not allowed in the room (ATI TEAS FAQs).
So the real question is not whether you get a calculator but how much it helps. It is a simple one: no parentheses, no exponent key, no fraction button, no scientific functions. It does the arithmetic; you still have to set the problem up, keep the order of operations, convert units and fractions, and round at the right moment. Below: what the calculator does and doesn't do, where it saves time and where it costs time, the mistakes that lose points, and a 7-day drill so it feels familiar on test day.
What calculator do you get on the TEAS?
A basic on-screen calculator, opened from the exam screen. ATI's FAQ says it is built into the exam and that you can't bring your own (ATI TEAS FAQs). We did not find a full list of its keys on ATI's public pages. Third-party guides that describe it agree on the core and differ on the extras:
| Key or feature | What guides report | Plan on it? |
|---|---|---|
| + − × ÷ | Every description includes them | Yes |
| Decimal point, clear, backspace | Included | Yes |
| Percent and square root | Listed by some guides, not by others | Don't count on them |
| Memory keys (M+, M−, MR) | Listed by one guide | Don't count on them |
| Parentheses | Not included | No |
| Exponents, fractions, scientific or graphing functions | Not included | No |
The safe plan is to prepare as if you have only the four operations. If the percent or square root key is there on the day, it is a bonus; if you relied on it and it isn't, you lose time in the middle of a section.
Can you use a calculator on the TEAS at home?
Only the on-screen one. The at-home TEAS is a remote proctored exam: a proctor watches through your webcam, and the room rules are the same as at a center. A physical calculator on your desk is a prohibited item, just like a phone or notes (ATI room requirements for a remote TEAS). The built-in calculator works the same way in the remote exam.
What you can have, at home or at a center, is one blank sheet of scratch paper or a small dry-erase board and two writing instruments (ATI TEAS FAQs). That sheet is where you do everything the calculator can't. The full list of what to bring and leave behind is in TEAS exam day tips, and the remote setup is in proctored exams.
Can you use a scientific calculator on the TEAS?
No. You can't bring any calculator, scientific or basic. The math on the TEAS doesn't need one: ATI's Numbers and Algebra and Measurement and Data areas are arithmetic, fractions, decimals, percents, ratios, simple equations, conversions and reading charts (ATI exam details). If you practise on a phone's scientific calculator, switch it to its basic mode, so you don't build habits around keys you won't have.
Which TEAS sections have a calculator?
All four. You will use it most in two:
- Mathematics (38 questions, 57 minutes): percent change, unit prices, dosage-style ratios, area and volume, averages. The math section has the most time per question, about 1.5 minutes, but word problems use it up fast. See how to pass TEAS math.
- Science (50 questions, 60 minutes): chemistry questions on moles, concentration or balancing, and scientific reasoning questions that ask you to read a data table and compute a difference or a rate. Most science questions need no arithmetic at all, so the calculator matters only on a handful. See TEAS chemistry and TEAS scientific reasoning.
Reading and English rarely need it. A reading question might ask you to compare two numbers in a passage or a chart, but that is usually a simple subtraction.
What the TEAS calculator won't do for you
These are the jobs that stay on your scratch paper.
Order of operations
Many basic calculators work strictly left to right as you press keys. Type 3 + 4 × 2 into one and press = and you get 14, because it adds first. The correct answer, multiplying first, is 11. With no parentheses key, the fix is to work the expression in the order PEMDAS gives, writing each partial result down:
- Do anything in parentheses first: in 5 × (12 − 4), compute 12 − 4 = 8.
- Then powers, by repeated multiplication: 3² is 3 × 3 = 9.
- Then multiplication and division, left to right.
- Then addition and subtraction, left to right.
A test of the habit: (18 + 6) ÷ 4 − 2². Write 18 + 6 = 24, then 24 ÷ 4 = 6, then 2 × 2 = 4, then 6 − 4 = 2. Typed straight in, left to right, you'd get a wrong answer.
Fractions
There is no fraction key. Either work the fraction by hand (common denominators, multiply across) or turn it into a decimal: 3/8 is 3 ÷ 8 = 0.375. If the answer choices are fractions, you may need to turn your decimal back, so learn the common ones by heart: 1/8 = 0.125, 1/6 ≈ 0.167, 1/3 ≈ 0.333, 3/8 = 0.375, 5/8 = 0.625, 2/3 ≈ 0.667. Our TEAS fractions guide drills both directions.
Unit conversions
The calculator does the multiplying, but you must know the factor and which way to apply it. Converting 154 pounds to kilograms with 1 kg ≈ 2.2 lb means dividing: 154 ÷ 2.2 = 70 kg. Multiplying gives 338.8, which a quick sense check rules out (a kilogram is heavier than a pound, so the kilogram number must be smaller). The factors to know are in TEAS math formulas and conversions.
Percent problems
Even with a % key, set percent problems up yourself. A price goes from $40 to $50: the change is 10, and the percent change is 10 ÷ 40 = 0.25, or 25%. Dividing by the new value (10 ÷ 50 = 20%) is the classic wrong answer, and it will be among the choices.
Rounding
Keep full decimals until the last step, then round as the question asks ("to the nearest tenth"). Rounding early in a two-step problem can push you to the wrong choice, and on a fill-in-the-blank question there are no choices to rescue you.
Negative numbers
Some basic calculators have no +/− key. For −7 × 3, multiply 7 × 3 = 21 and apply the sign yourself: negative times positive is negative, so −21.
When mental math is faster than the calculator
Clicking a calculator with a mouse is slower than typing on a keypad. On a timed section, these are quicker in your head:
| Task | Head method | Example |
|---|---|---|
| 10% of a number | Move the decimal one place left | 10% of 85 = 8.5 |
| 5%, 20%, 50% | Half of 10%, double 10%, half | 20% of 85 = 17 |
| × or ÷ 10, 100, 1,000 | Move the decimal | 2.5 L = 2,500 mL |
| Ruling out answer choices | Estimate first | 19 × 21 is about 400, so 3,990 is wrong |
| Simple ratios | Scale both sides | 2 tablets per 50 kg → 4 per 100 kg |
The best habit is both: estimate in your head, compute on the calculator, then check the two agree. If they don't, one of them has a slip, and it is usually the calculator entry.
TEAS calculator mistakes that cost points
| Mistake | What happens | The fix |
|---|---|---|
| Typing a whole expression in one go | Left-to-right result, wrong order of operations | Work in PEMDAS order, write partial results |
| Not clearing between steps | The last result gets added to the next problem | Press clear before each new problem |
| Dividing the wrong way | Answer off by a factor (338.8 kg instead of 70) | Write the units and check the size makes sense |
| Rounding in the middle | Final answer lands between two choices | Keep decimals, round once at the end |
| Using it for everything | Minutes lost on clicks | Head math for 10%, powers of ten, estimates |
| Practising only on a phone | Mouse clicks feel slow on the day | Practise on a computer's basic calculator with a mouse |
A 7-day TEAS calculator drill
Fifteen minutes a day, on a computer, using a basic calculator in standard mode clicked with the mouse (not the keyboard), with one sheet of scratch paper beside you:
| Day | Drill |
|---|---|
| 1 | 10 order-of-operations expressions, each with parentheses and one power, by PEMDAS steps |
| 2 | 10 fraction problems: half by hand, half by decimal, check they match |
| 3 | 10 conversions (lb and kg, inches and cm, mL and L, °F and °C), writing units each time |
| 4 | 10 percent problems: percent of, percent change, original price before a discount |
| 5 | 10 word problems timed at 1.5 minutes each, estimate first |
| 6 | 5 chemistry and 5 data-table science questions that need arithmetic |
| 7 | A timed math section: 38 questions in 57 minutes, calculator on screen only |
Our free practice sets are built for this: 24 TEAS math practice questions and 20 worked word problems. To see whether math is even your biggest gap, take the free TEAS practice test first: it scores all four sections against your program's minimum.
TEAS calculator FAQ
Do you get a calculator on the TEAS exam?
Yes, a basic calculator built into the exam screen, in every section.
Can I bring my own calculator to the TEAS?
No. Personal calculators are not allowed, at a test center or at home.
Can you use a calculator on the TEAS 7?
Yes. The TEAS 7, the current version since June 2022, has the on-screen calculator. Older advice about bringing a calculator is out of date (is there a new TEAS).
Does the TEAS calculator have a square root key?
Guides disagree, and ATI doesn't publish a key list. Learn the perfect squares up to 15² = 225, so you don't need it.
Is scratch paper allowed?
Yes: one blank sheet or a small dry-erase board, and two writing instruments.
Will the TEAS give me the conversion factors?
Don't count on it. Learn the common ones (metric prefixes, 1 kg ≈ 2.2 lb, 1 inch = 2.54 cm) before test day.
Sources
- ATI, ATI TEAS exam and other FAQs (calculator, scratch paper, ID). Read 2026-10-19.
- ATI, Room requirements for a remote at-home TEAS. Read 2026-10-19.
- ATI, TEAS exam details. Read 2026-10-27.
- Open Exam Prep, Test-taking and calculator strategies (an independent guide's description of the keys). Read 2026-11-04.
More on the test itself: what is on the TEAS test, TEAS unscored questions, nursing school entrance exams, or all TEAS guides. Then take the free TEAS practice test to see where your points are.