Basic Calculator
Basic Arithmetic Calculator works out Result and Unrounded result from Input style, Expression and First number. The default figures on this page give result of 33; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
3 steps
- Evaluate 12 + 7 × 3 using standard operator precedence.
- 7 × 3 = 21 → 12 + 21
- 12 + 21 = 33 → 33
Step-by-step workingtable
Its 12 worked examples are re-run on every release, last on 15 September 2026. What changed
Sources and references
4 sources
What the Basic Arithmetic Calculator calculates
Adds, subtracts, multiplies, divides and exponentiates numbers, either as a free-form expression evaluated with correct operator precedence, as two named operands, as a list folded left to right, or as a sum written out in words — in binary floating point or in exact fraction arithmetic.
How to use this Basic Arithmetic Calculator
Enter Input style, Expression, First number and Second number. Result updates as you type, and “Use a worked example” loads checked figures you can adjust. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Result, Unrounded result and Expression evaluated.
The method follows ISO 80000-2, Quantities and units — Part 2: Mathematics (operator symbols and precedence), NIST Digital Library of Mathematical Functions, §1.1 Notation, IEEE 754-2019, Standard for Floating-Point Arithmetic and Unicode CLDR number formatting patterns (es-ES decimal comma, en-IN lakh/crore grouping).
Precedence: 12 + 7 * 3 example
With Input style: expression, Expression: 12 + 7 * 3, the calculator returns Unrounded result: 33, Expression evaluated: 12 + 7 * 3. This example is checked against an independent source in the test suite.
What you can compare
Change one input at a time to see how it affects Result, Unrounded result and Expression evaluated. The inputs you can vary are Input style, Expression, First number, Second number, Operation and Numbers.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
See something wrong? Report a problem with this calculator
Frequently asked questions
What is the best basic calculator for beginners?
Adds, subtracts, multiplies, divides and exponentiates numbers, either as a free-form expression evaluated with correct operator precedence, as two named operands, as a list folded left to right. On this page it is computed from Input style, Expression and First number and shown as Result, Unrounded result and Expression evaluated.
What is a basic calculator called?
It needs Input style, Expression, First number, Second number, Operation and Numbers. Nothing else is required, and the figures stay in your browser.
Is a TI-84 considered a basic calculator?
Adds, subtracts, multiplies, divides and exponentiates numbers, either as a free-form expression evaluated with correct operator precedence, as two named operands, as a list folded left to right. Put your own figures in above and the working updates beside the result. For scale, the default figures on this page give 33.
What information do I need for the Basic Arithmetic Calculator?
You need Input style, Expression, First number, Second number, Operation, Numbers, Arithmetic and Variables (optional). The page opens with default figures that give result of 33, so you can see the scale before entering your own.
What does this Basic Arithmetic Calculator show?
It shows Result, Unrounded result, Expression evaluated, Result with separators, Result as a fraction, Whole-number quotient, Remainder and Operation, with the working and any warnings for your entries.
Can I check how the Basic Arithmetic Calculator result was calculated?
Yes. The “How this is worked out” section shows the calculation steps, and the sources section identifies the references used for the method.