Online Calculator — Free, No Registration Required

Easily perform your daily calculations with our reliable and user-friendly online calculator, designed for quick and accurate results.

  • Instant result
  • No sign-up
  • Visible assumptions
  • Deterministic calculation

In 30 seconds: Access a simple and free calculator for all your basic arithmetic needs anytime, anywhere. Deterministic calculation with auditable formulas. The result is indicative — adjust the assumptions to reflect your real operation.

Methodology

Add · subtract · multiply · divide · modulo (%)

Power: a^b · square: a^2

Square root: sqrt(x)

Trigonometry: sin(x) · cos(x) · tan(x) — RAD or DEG

Inverse: asin(x) · acos(x) · atan(x)

Logarithms: log(x) base 10 · ln(x) base e

Exponential: exp(x) = e^x

Constants: π · e

Parentheses to group

Variables

Expression
Any valid combination of numbers, operators, functions, and constants.
Angle mode
RAD (default) or DEG — only affects sin/cos/tan and inverses.
Ans
Last computed result. Useful for chained operations.

Practical example

Multiplication: 250 × 1.16 = 290

Tip / tax calc: 1500 × 0.16 = 240

Power: 2^10 = 1024

Square root: sqrt(81) = 9

Trig in degrees: sin(30) in DEG mode = 0.5

Chained: (12 + 8) × 5 / 4 = 25

Interpretation

Supports unlimited parentheses; respects standard operator precedence (power > multiply/divide > add/subtract).

Switch RAD/DEG with one click — changes affect future evaluations only.

Use Ans to reuse the previous result without retyping.

Keyboard shortcuts: Enter to evaluate, Backspace to delete, Escape to clear.

Assumptions and limitations

  • General-purpose calculator — real numbers in IEEE 754 double precision (~15-17 significant digits).
  • For arbitrary precision (heavy scientific computing) use a dedicated CAS tool.
  • DEG mode applies conversion only to sin/cos/tan/asin/acos/atan; other functions use their natural scale.

When to use this calculator

  • Quick operations: percentages, conversions, tips, splitting bills.

  • Academic work: math, physics, chemistry homework — full trig and log support.

  • Verify spreadsheet results or physical calculator output without installing anything.

  • Quick calculations in your work browser without opening Excel or Calculator.app.

  • Professionals needing scientific functions (engineering, advanced finance) without downloading software.

Common mistakes

  • Forgetting parentheses in complex operations: 2+3×4 = 14, not 20. Use (2+3)×4 if you meant 20.

  • Confusing RAD and DEG in trig: sin(90) in RAD ≈ 0.894, in DEG = 1. Verify the active mode.

  • Thinking log(x) is base e: here log(x) is base 10; use ln(x) for base e.

  • Division by zero: the calculator shows 'Division by zero' instead of 'Infinity' for clarity.

  • Using 'e' as a variable: 'e' is reserved as a constant (≈ 2.71828).

Industry use cases

Students

Math, physics, chemistry homework — full support for trig, logarithms, exponentials.

Finance professionals

Validate compound powers (1+r)^n, manual NPV, quick checks without opening Excel.

Engineers

sin, cos, tan, roots, arbitrary powers for quick browser-based calculations.

Daily life

Add up bills, calc tips, split expenses, convert percentages — clean UI, full keyboard support.

Educators

Share calculations via link (inputs preserve in URL for sharing solved exercises).

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Calculator guide

What it calculates and who it is for

This is a scientific expression calculator: instead of typing one operation at a time, you write the full expression — with parentheses, powers, trigonometric functions and constants — and the engine evaluates it respecting the order of operations.

It serves students and professionals who need multi-step calculations without carrying intermediate results by hand: the expression stays visible, can be corrected and re-evaluated, and the angle mode (degrees or radians) is controlled explicitly.

Inputs

Expression
The whole operation on one line: numbers, operators (+, −, ×, ÷, %, ^), parentheses, functions and constants. Example: 12*(8+5)-3^2.
Available functions
Trigonometric and their inverses (sin, cos, tan, asin, acos, atan), square root (sqrt), logarithms (log base 10, natural ln), exponential (exp) and absolute value (abs).
Constants
π (pi) and e, at double-precision floating-point accuracy.
Angle mode
DEG (degrees) or RAD (radians): defines how arguments of trigonometric functions and their inverses are interpreted.

Results you get

Result
The numeric value of the expression evaluated under the standard order of operations.
Explained errors
If the expression is invalid — unclosed parentheses, division by zero, out-of-domain argument — the engine states the problem instead of returning a misleading value.

Methodology and assumptions

Precedence: parentheses → functions → powers (^) → multiplication, division and modulo (× ÷ %) → addition and subtraction

sin(30) in DEG mode = 0.5; the same expression in RAD uses the argument in radians

The expression is parsed with a formal precedence grammar: each operator binds according to its level, and powers evaluate before multiplication, which precedes addition. It is the same convention as written algebra.

The engine uses double-precision floating-point arithmetic (IEEE 754): exact for most practical uses, with the rounding limits inherent to binary decimals.

Invalid inputs fail explicitly: the evaluator validates syntax and each function's domain before returning a result.

Worked example

Hypothetical example for illustration. The numbers reproduce exactly when entered into the calculator on this page.

Worked example 1: 12*(8+5)-3^2. The parenthesis resolves first (13), then the power (3^2 = 9), then the multiplication (12 × 13 = 156) and finally the subtraction: 156 − 9 = 147.

Worked example 2: sin(30) in DEG mode = 0.5. The same argument in RAD mode would give the sine of 30 radians — an entirely different value: the angle mode matters.

Worked example 3: sqrt(2)*10 = 14.1421 (the square root of 2 times 10, at standard floating-point precision).

How to interpret the result

The value of writing the full expression is that the calculation stays auditable: you can reread exactly what you computed, fix a parenthesis and re-evaluate, instead of reconstructing an invisible chain of keystrokes.

If a result surprises you, check precedence first: 12*8+5 is not the same as 12*(8+5). The most common mistake in expression calculators is omitting parentheses where the intent required them.

In trigonometry, confirm the angle mode before evaluating: it is the number-one cause of 'wrong' results that are actually correct for the active mode.

Limitations and when not to use it

  • Floating-point arithmetic: some binary decimals produce tiny rounding effects (around 15-16 significant digits). For exact fraction arithmetic or arbitrary precision, use specialized tools.
  • It does not solve equations or isolate variables: it evaluates closed numeric expressions.
  • It does not handle complex numbers: even roots of negatives and invalid domains return an explicit error.
  • It does not replace the site's financial calculators: compound interest, loans and margins have dedicated tools with documented formulas.
  • The % operator is modulo (division remainder), not percentage: to compute 15% of 80, write 80*15/100.

From theory to calculation

The calculator on this page runs with your numbers — no forms, no login. Scroll up and try it.

Try the calculator

Frequently asked questions

1How do I compute a percentage?
With explicit multiplication: 15% of 80 is 80*15/100 = 12. The % symbol in this calculator is the modulo operator — 10%3 returns 1, the remainder of dividing 10 by 3.
2Why doesn't sin(30) give me 0.5?
You are in RAD mode: 30 is interpreted as radians. Switch to DEG to work in degrees; in DEG, sin(30) = 0.5 exactly as expected.
3Can I nest functions and parentheses?
Yes, to any reasonable depth: sqrt(abs(-16)) evaluates the absolute value first, then the root. Every opened parenthesis must close or the evaluator will flag the error.
4What does a domain error mean?
That the function is undefined for that argument: square root of a negative, logarithm of zero or a negative, asin of a value outside [−1, 1]. The engine prefers warning you over returning a meaningless number.
5Are the results exact?
They are exact within standard double-precision arithmetic (about 15-16 significant digits), the same used by spreadsheets. You may see binary rounding effects in some decimals — normal and harmless for everyday use.

Last updated: July 19, 2026

View methodology

How this simulator was reviewed

What you'll see, what it prevents, and where you shouldn't trust it

Every simulator on Simúlalo ships with the same editorial structure: two hypothetical worked examples with numbers, the errors it helps you avoid, the model's declared limitations, and a visible financial disclaimer. The review is signed and dated.

Hypothetical caseCase A

Student needing to evaluate an expression with powers, roots, and order of operations

A student wants to calculate (3.4 × 10⁵) + √(625) − 2³ step by step. The online scientific calculator evaluates: 3.4 × 10⁵ = 340,000; √625 = 25; 2³ = 8. Result: 340,017. The calculator respects the order of operations (parentheses, exponents, multiplication/division, addition/subtraction) and accepts the full expression in a single line. Decision: for problems with multiple operators, writing the full expression and letting the calculator apply hierarchy avoids step-by-step errors.

Illustrative figures. Does not represent a real company or an investment recommendation.

Hypothetical caseCase B

Professional converting from degrees to radians for a trigonometric function

An engineer needs to compute sin(45°). In degrees mode, sin(45°) = 0.7071. In radians mode, sin(45) ≈ 0.8509 — a VERY different value because 45 radians is a huge angle (approximately 7 turns plus some more). Decision: before using trigonometric functions, verify whether the calculator is in degrees or radians mode. Switching mode is the most common cause of calculation errors in students and professionals who don't use the tool daily.

Illustrative figures. Does not represent a real company or an investment recommendation.

Common mistakes it helps you avoid

Things a team or decision-maker might assume that this simulator forces you to verify before committing.

  • Forgetting the order of operations. Writing 2 + 3 × 4 expects 14 (multiplication first), not 20. To add first, use parentheses: (2 + 3) × 4 = 20.
  • Confusing degrees and radians. In degrees mode, sin(90) = 1. In radians mode, sin(90) ≈ 0.894. Results are completely different by mode.
  • Using parentheses incorrectly. Every opening parenthesis needs a closing one. Calculators usually flag the error on evaluation; check the count before pressing equal.
  • Assuming 'log' is base 10 without verifying. Some calculators use 'log' for natural log (base e). Verify the tool's documentation before computing.

Model limitations

What the simulator does not do, and where you need a professional or a specialized tool.

  • Does not replace a Computer Algebra System (CAS). To solve symbolic equations, differentiate, or integrate formulas, you need a specific CAS.
  • Does not graph functions. For graphic visualization use GeoGebra, Desmos, or dedicated software.
  • Works with limited precision (typically 15-16 decimal digits). Scientific calculations requiring more precision need specialized tools.
  • Does not maintain persistent memory between sessions unless the browser allows it. If you refresh the page, stored values are lost.

When NOT to use this simulator

For high-precision calculations in structural engineering, analytical chemistry, or theoretical physics, a generalist online calculator does not substitute professional software (MATLAB, Mathematica, Python with NumPy, etc.). For educational problems, high school exercises, or everyday calculations it is sufficient; for publishable academic work or engineering decisions with life risk, use certified tools.

Financial notice

Results are illustrative estimates and do not constitute financial, tax, accounting, or legal advice. Use the results as a reference point and validate important decisions with a certified professional.

Editorial review

Reviewed by the Simúlalo editorial team

This simulator was reviewed by the people listed below before being published. The review covers the declared formula, the model's assumptions, the explicit limitations, and the absence of unsupported financial claims.

They are part of the Simúlalo editorial team, focused on building financial tools that are clear, educational, and easy to interpret.

Last updated: We update this page when the methodology, sources used, or simulator structure change.

This tool uses standard financial formulas and user-supplied data. To explain concepts like rates, credit, risk, or cash flow we consult public and official sources (Banxico, SAT, CONDUSEF, CNBV, Banco de España, IFRS, BIS, among others). Simúlalo is not affiliated with, sponsored by, or endorsed by these institutions.