Math Calculators

From homework to engineering, solve math problems in seconds with free online math calculators. Fast, accurate results on any device — no sign-up required.

Available Math Calculators

• Proportion Calculator — Solve proportions and find missing values in ratios instantly.
• Fraction Calculator — Add, subtract, multiply & divide fractions easily.
• Percentage Calculator — Calculate percentages, percent change and discounts instantly.
• Scientific Calculator — Advanced calculator with trigonometry, logarithms and powers.
• Volume Calculator — Find the volume of spheres, cubes, cylinders and more.
• Area Calculator — Find the area of rectangles, circles, triangles and more.
• Binary / Hex Calculator — Convert between binary, decimal, octal and hexadecimal.
• Exponent Calculator — Raise any base to any power, with roots and scientific notation.
• Mean / Median / Mode Calculator — Average, middle value and most frequent number from any list.
• Probability Calculator — Combinations, permutations, odds and coin-flip streaks.
• Quadratic Formula Calculator — Solve ax²+bx+c=0 with real or complex roots, discriminant and vertex.
• Random Number Generator — Pick random integers in any range, with or without duplicates.
• Standard Deviation Calculator — Population and sample SD, variance and mean from any number list.
• Statistics Calculator — Mean, median, mode, range, variance and standard deviation for any dataset.
• Triangle Calculator — Area via Heron’s formula, hypotenuse, perimeter and angles from any 3 sides.
• Matrix Calculator — Add, multiply, determinants.
• P-Value Calculator — Z-score to p-value.
• Prime Factorization Calculator — Prime factors with exponents.
• Slope Calculator — Slope and line equation.
• Z-Score Calculator — Standard score and percentile.
• Ratio Calculator — Solve, simplify and scale ratios.
• Confidence Interval Calculator
• GCF Calculator
• Half-Life Calculator
• LCM Calculator
• Log Calculator

Coming Soon

Frequently Asked Questions

Are these math calculators really free?

Yes — every math calculator on Sigma Calculator is 100% free, with no sign-up and no limits on calculations.

What math topics are covered?

Fractions, percentages, algebra, statistics, geometry basics, probability, and more — from elementary arithmetic to college-level topics.

Can I use these calculators for homework?

Yes — they are great for checking homework and learning. We recommend working through problems yourself first, then verifying with the calculator.

How accurate are the results?

Very accurate — all calculators use standard mathematical formulas and double-precision arithmetic in your browser.

Do these calculators work on mobile?

Yes — every calculator is 100% mobile friendly and works instantly on any phone, tablet, or desktop.