Free Online Scientific Calculator for Fast, Accurate Results
Calculate expressions in seconds with CalcSolver. Use the scientific keypad for arithmetic, fractions, powers, roots, logarithms and trigonometry. Enter your problem, choose DEG or RAD, and get a clear numerical result — free in your browser, with no account or download.
Calculate your answer to calculate. Use DEG/RAD for trigonometry.
Popular calculations, ready to check
Quick reference answers for fractions, percentages, roots and trigonometry. Use them to check your working or try a similar calculation.
Explore math calculators and practice tools
Choose a focused tool for the topic you are working on. Practise core number skills, check calculations and review the method behind selected problems.
Scientific Calculator
Evaluate trigonometric functions, logarithms, roots, powers and factorials with one scientific keypad.
Fraction to Decimal Converter
Convert common fractions into decimal and percentage forms to check equivalent values.
Fraction Simplifier
Reduce a fraction to its simplest form using the greatest common factor.
LCM and GCF Calculator
Find the least common multiple and greatest common factor for a set of numbers.
Prime Number Checker
Check whether a number is prime and explore its factors.
Divisibility Rules Checker
Check whether a number is divisible by common integers from 2 to 10.
Multiplication Table Generator
Review multiplication facts with tables up to 20.
Place Value Calculator
Break a number into place values, from ones and tens to larger positions.
Loan Payment Calculator
Estimate a loan payment using the amount, interest rate and repayment term.
Find the right math tool for your level
Browse by school level and choose a topic that matches the maths you are practising.
Grades 9–12
Strengthen algebra, trigonometry, logarithms and early calculus ideas.
Grades 6–8
Sharpen fractions, factors, multiples and decimals.
Grades 3–5
Grow number sense, place value and times-table fluency.
How to use the online calculator
Enter an expression, calculate the result and use the topic tools to practise related skills.
Enter your expression
Enter numbers, operators, brackets, roots or supported functions. For example (25 + √81 − 2) ÷ (3 × 2).
Calculate your answer
Press Enter or tap the equals key. The calculator evaluates the expression and displays the numerical result.
Practise the topic
Open a related fraction, factor or prime-number tool to practise the underlying concept.
Worked math examples
Follow these sample problems to review common methods. Enter supported expressions in the calculator to verify the numerical result.
Solve a quadratic
- Identify a = 1, b = −5 and c = 6.
- Find the discriminant: b² − 4ac = 25 − 24 = 1.
- Apply the quadratic formula: x = (5 ± 1) / 2.
Evaluate a trig expression
- Put the calculator in degree mode.
- sin(30°) = 0.5 and cos(60°) = 0.5.
- Add them: 0.5 + 0.5.
Reduce a fraction
- Find the greatest common factor of 18 and 24, which is 6.
- Divide the top and bottom by 6.
- 18 ÷ 6 = 3 and 24 ÷ 6 = 4.
Find the LCM and GCF
- Factorise: 24 = 2³ × 3 and 36 = 2² × 3².
- For the GCF, take the lowest powers: 2² × 3 = 12.
- For the LCM, take the highest powers: 2³ × 3² = 72.
Work out a percentage change
- Find the change: 100 − 80 = 20.
- Divide by the starting value: 20 ÷ 80 = 0.25.
- Multiply by 100 to get a percentage.
Use the remainder theorem
- For the divisor (x − 2), set a = 2 and evaluate P(2).
- P(2) = 2(2³) − 3(2) + 5.
- That gives 16 − 6 + 5.
A practical math resource for everyday learning
Use the calculator to check work, review formulas and practise key maths topics at home or in the classroom.
Quick calculations
Enter an expression and calculate it directly in the page. Results are displayed without a separate app installation.
Use the keypad or keyboard
Type an expression into the input field or use the on-screen keypad. Press Enter or equals to evaluate it.
DEG and RAD modes
Switch angle units before evaluating sine, cosine or tangent expressions.
Responsive calculator layout
The calculator layout adapts to desktop, tablet and mobile browser screens.
Use it across devices
Open CalcSolver in a modern browser on a phone, tablet, Chromebook or desktop.
No account required
Start calculating in your browser without creating an account or installing software.
Math help for students, teachers and families
Students
Check calculations, practise new topics and use examples to review your understanding.
Teachers and tutors
Use the scientific keypad to demonstrate calculations and share focused practice tools with learners.
Parents
Review school maths concepts and work through examples with your child.
Essential math formulas and identities
Browse frequently used formulas for algebra, trigonometry, fractions, geometry and statistics.
Fractions, decimals and percents at a glance
Equivalents worth memorising, or checking against the calculator.
| Fraction | Decimal | Percent |
|---|---|---|
| 1/2 | 0.5 | 50% |
| 1/3 | 0.3333 | 33.33% |
| 2/3 | 0.6667 | 66.67% |
| 1/4 | 0.25 | 25% |
| 3/4 | 0.75 | 75% |
| 1/5 | 0.2 | 20% |
| 1/8 | 0.125 | 12.5% |
| 7/8 | 0.875 | 87.5% |
Common calculator mistakes to watch for
A small input mistake or incorrect angle setting can change a result. Check these points before calculating.
Forgetting the order of operations
Check your brackets and operator order before evaluating a long expression. For example, 6 ÷ 2 × (1 + 2) is 9, because multiplication and division run left to right.
Mixing degrees and radians
Check the angle mode first: sin(90) is 1 in degrees, but a different value in radians.
Dropping a negative sign
Note that −3² is −9, while (−3)² is 9. Brackets change the answer.
Rounding too early
Keep full precision until the final step; rounding along the way can change the last digits.
Mistyping a percent
15% means 0.15. Entering 15 instead of 0.15 makes “15% of 80” come out as 1,200 rather than 12.
Online scientific calculator: functions and guide
Learn how to enter expressions, use scientific functions and choose the right math tool for common calculations.
Scientific calculator functions
Use powers, square and cube roots, logarithms, factorials and trig functions such as sin, cos and tan. Brackets let you group operations and build longer expressions.
Solving quadratic equations
A quadratic equation looks like ax² + bx + c = 0, and the quadratic formula solves it: x = (−b ± √(b² − 4ac)) / 2a.
Algebra and the Remainder Theorem
Evaluate polynomials and use the Remainder Theorem to find what is left over when a polynomial is divided by a linear expression. To divide P(x) by (x − a), just work out P(a).
Percentage change
Percentage change = (new value − original value) ÷ original value × 100. Going from 80 to 100 is a 25% increase.
Online calculator or manual calculation?
| Feature | CalcSolver | Spreadsheet | Hand calculation |
|---|---|---|---|
| Cost | Free | Free or paid | Free |
| Setup time | None | Build formulas | None |
| Trig and log functions | Built in | Needs formulas | Tables or memory |
| Works on a phone | Yes | Limited | Yes |
| Risk of errors | Low | Medium | Higher |
Keyboard shortcuts
| Key | What it does |
|---|---|
| Enter or = | Evaluate the expression |
| Esc | Clear the expression and reset the result |
| ← → | Move the cursor inside the expression |
| Backspace | Delete the character before the cursor |
| Tab | Jump to the DEG/RAD toggle and keypad |
Common questions
Math guides and learning resources
Explore approachable guides, worked examples and formula references for common maths topics.
Understanding the Basics of Calculus
Derivatives and integrals, minus the jargon.
The Magic of Prime Numbers & Encryption
Why primes matter for maths and online security.
The Polynomial Remainder Theorem Made Simple
Find polynomial remainders with P(a) — no long division needed.
Ready to calculate?
Use the scientific calculator for your next expression, review a worked example or choose a topic tool. CalcSolver is free to use online.