Free Percentage & Math Calculators
High-precision calculation tools with step-by-step arithmetic, visual diagrams, and verifiable proofs. Designed for students, educators, and everyday calculations.
Percentages
Solve any percentage problem: percentage of a number, percentage change, difference, discounts, and additions with clear step-by-step math.
Fractions
Perform fraction operations, simplify to lowest terms, and convert mixed numbers with exact step-by-step working and visual bar models.
Ratios & Proportions
Simplify ratios of 2 or 3 numbers and solve proportional equations (a:b = c:x) with cross-multiplication proofs and split bar diagrams.
Averages & Statistics
Calculate arithmetic mean, median of odd and even sets, and weighted grade averages with full mathematical formulas and clear explanations.
Scientific Notation
Convert standard numbers to scientific and engineering notation, and perform exact arithmetic (+, -, ×, ÷) with normalized exponents.
Popular Online Calculators
Jump straight into our most frequently used arithmetic and algebraic tools.
Percentage Calculator
Calculate what is P percent of number Y instantly with clear step-by-step arithmetic, visual percentage bar, and custom decimal rounding.
What Percent Is X of Y?
Find out what percentage X represents out of total Y with instant step-by-step fraction reduction and visual proportion ring.
Percentage Change Calculator
Calculate percentage increase or decrease between initial and final values with exact mathematical working and comparison charts.
Percentage Difference Calculator
Calculate the percentage difference between two positive numbers compared against their arithmetic average with step-by-step steps.
Add or Subtract a Percentage
Increase or decrease any quantity by a given percent (e.g. markup, tip, tax, or discount) with transparent step-by-step calculations.
Discount Calculator (Percent Off)
Compute final sale price, total dollar savings, and stacked successive discounts with verified commercial shopping math.
Fraction Calculator
Perform fraction operations with common denominators, cross-multiplication, step-by-step reductions, and visual fraction bar models.
Simplify Fractions Calculator
Reduce any proper or improper fraction to simplest form using prime factorization and greatest common divisor (GCD) working.
Ratio Calculator
Simplify 2-term and 3-term ratios to lowest whole-number integers with step-by-step decimal scaling and greatest common divisor proofs.
Proportion Calculator
Solve proportional equations (A/B = C/D) for any missing variable with step-by-step cross-multiplication and verification.
Average (Mean) Calculator
Calculate the arithmetic mean of any list of numbers with sum breakdown, count, and precise step-by-step mathematical working.
Median Calculator
Find the median of any dataset. Handles both odd counts (exact middle) and even counts (average of two middle numbers) with ordered steps.
How We Build and Test Our Calculators
Most online calculators suffer from JavaScript floating-point representation bugs (such as 0.1 + 0.2 rendering as 0.30000000000000004). At CalcStep, we hold our tools to uncompromising mathematical standards.
Arbitrary Precision
All decimal operations run via decimal.js with 35-digit internal precision and standard half-away-from-zero rounding.
Exact BigInt Fractions
Fractions, GCDs, and LCMs are computed natively using BigInt integers without numerical limits or precision decay.
Transparent Working
Every result includes an interactive, plain-language "Show steps" panel generated directly by the calculation engine.
Featured Math & Calculation Guides
In-depth tutorials with real-world examples, formula proofs, and common mistake breakdowns.
How to Calculate Percentage
Master percentage calculations with intuitive formulas, step-by-step methods, shortcuts, and practical real-world examples for tips, taxes, and tests.
Percent Change vs. Percentage Difference vs. Percentage Points Explained
Learn the critical differences between percent change, percentage difference, and percentage points with clear mathematical formulas and real scenarios.
How to Simplify Fractions
Discover how to reduce fractions to simplest form using prime factorization, greatest common divisor (GCD), and mental math shortcuts.
Mean, Median, and Mode
Understand when to use the mean, median, or mode. Learn how outliers skew averages and how to choose the right statistical measure for your data.
How to Read and Write Scientific Notation
Learn how to read, write, and calculate with scientific notation. Master mantissas, powers of 10, positive and negative exponents with examples.
Ratios and Proportions Explained
A comprehensive guide to understanding ratios, scaling recipes, solving proportions with cross-multiplication, and simplifying multi-term ratios.
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