Math calculators
Algebra, geometry, statistics, percentages. Step-by-step working shown alongside the answer.
All math tools
68 tools, each runs locally in your browser. Click any card to open it.
Rectangle, square, triangle, circle, trapezoid, parallelogram, ellipse, sector.
Aspect Ratio Calculator takes numbers, ranges, parameters and returns the matching aspect ratio result. Runs entirely …
Binary Encoder / Decoder takes source value and source unit and returns the matching binary encoder / decoder result. …
Binary to Text Converter takes source value and source unit and returns the matching binary to text result. Runs entir…
A Binary Decimal Hex Converter converts data from one format to another using a deterministic mapping. It parses the i…
Body Water Percentage Calculator computes percentage result from two values, operation (of/increase/decrease/change). …
Circle Calculator takes numbers, ranges, parameters and returns the matching circle result. Runs entirely in your brow…
Coffee Water Ratio Calculator takes numbers, ranges, parameters and returns the matching coffee water ratio result. Ru…
Color Contrast Ratio (WCAG) takes numbers, ranges, parameters and returns the matching color contrast ratio (wcag) res…
Combinations + Permutations (nCr, nPr) takes numbers, ranges, parameters and returns the matching combinations + permu…
Cone Volume Calculator takes numbers, ranges, parameters and returns the matching cone volume result. Runs entirely in…
Confidence Interval Calculator takes sample data, hypothesis, confidence level and returns the matching confidence int…
Correlation Coefficient takes sample data, hypothesis, confidence level and returns the matching correlation coefficie…
Cylinder Volume Calculator takes numbers, ranges, parameters and returns the matching cylinder volume result. Runs ent…
Debt-to-Income (DTI) Calculator computes front-end and back-end DTI % from monthly gross income, total monthly debt pa…
Discount Percentage Calculator computes percentage result from two values, operation (of/increase/decrease/change). Ru…
Ellipse Area Calculator takes numbers, ranges, parameters and returns the matching ellipse area result. Runs entirely …
Email Subject Tester takes source text, target style, optional rules and returns the matching email subject tester res…
Factorial Calculator (n!) takes numbers, ranges, parameters and returns the matching factorial calculator (n!) result.…
Fraction Calculator takes numbers, ranges, parameters and returns the matching fraction result. Runs entirely in your …
GCF & LCM Calculator takes numbers, ranges, parameters and returns the matching gcf & lcm result. Runs entirel…
Great Circle Distance takes numbers, ranges, parameters and returns the matching great circle distance result. Runs en…
A Hex / Binary / Decimal Converter converts data from one format to another using a deterministic mapping. It parses t…
Hex Encoder / Decoder takes source value and source unit and returns the matching hex encoder / decoder result. Runs e…
Hex to HSV Converter takes source value and source unit and returns the matching hex to hsv result. Runs entirely in y…
Hex to RGB Converter takes source value and source unit and returns the matching hex to rgb result. Runs entirely in y…
Hex to Text Converter takes source value and source unit and returns the matching hex to text result. Runs entirely in…
Count seconds between flash and thunder. Divide by 5 for miles.
log b (x) for any base. Auto-shows log₁₀, ln, log₂.
Marinade Ratio Calculator takes numbers, ranges, parameters and returns the matching marinade ratio result. Runs entir…
Mean Median Mode Calculator takes sample data, hypothesis, confidence level and returns the matching mean median mode …
THX: 36° FOV. Sit 1.5× to 2.5× screen diagonal away.
Paint Mixing Ratio Calculator takes numbers, ranges, parameters and returns the matching paint mixing ratio result. Ru…
Parallelogram Area Calculator takes numbers, ranges, parameters and returns the matching parallelogram area result. Ru…
Percentage Calculator computes percentage result from two values, operation (of/increase/decrease/change). Runs entire…
Percentage Change Calculator computes percentage result from two values, operation (of/increase/decrease/change). Runs…
Permutation & Combination takes numbers, ranges, parameters and returns the matching permutation & combination…
Length × width × avg-depth × 7.48 = US gallons.
Pyramid Volume Calculator takes numbers, ranges, parameters and returns the matching pyramid volume result. Runs entir…
Pythagorean Theorem Calculator takes numbers, ranges, parameters and returns the matching pythagorean theorem result. …
Quadratic Equation Solver takes numbers, ranges, parameters and returns the matching quadratic equation solver result.…
Ratio + Proportion Calculator takes numbers, ranges, parameters and returns the matching ratio + proportion result. Ru…
RGB to Hex Converter takes string, regex, format, count and returns the matching rgb to hex result. Runs entirely in y…
Rice Water Ratio Calculator takes numbers, ranges, parameters and returns the matching rice water ratio result. Runs e…
Right Triangle Calculator takes numbers, ranges, parameters and returns the matching right triangle result. Runs entir…
Roman Numeral Converter takes source value and source unit and returns the matching roman numeral result. Runs entirel…
Speed = Distance ÷ Time. Solve for any of the three.
c = 299,792,458 m/s. Light reaches Sun in 8 min, Moon in 1.3 sec.
Sphere Volume + Surface Area takes numbers, ranges, parameters and returns the matching sphere volume + surface area r…
Standard Deviation computes standard deviation, variance from numeric dataset. Runs entirely in your browser. No login…
Compare two sample means. Significant if p < 0.05.
Trapezoid Area Calculator takes numbers, ranges, parameters and returns the matching trapezoid area result. Runs entir…
Triangle Area Calculator takes numbers, ranges, parameters and returns the matching triangle area result. Runs entirel…
Triangle Calculator takes numbers, ranges, parameters and returns the matching triangle result. Runs entirely in your …
Cube, sphere, cylinder, cone, pyramid, rectangular box, ellipsoid, capsule.
Waist-to-Height Ratio Calculator takes numbers, ranges, parameters and returns the matching waist-to-height ratio resu…
Waist-to-Hip Ratio Calculator takes numbers, ranges, parameters and returns the matching waist-to-hip ratio result. Ru…
Σ (score × weight) / Σ weights = final grade.
Z-Score Calculator takes sample data, hypothesis, confidence level and returns the matching z-score result. Runs entir…
Binary to Hex to Decimal to Octal Converter computes number in the chosen target base from number in any base (binary,…
binary octal Unix permissions chmod 755, base conversion binary to octal converter free 3tej calculator
hex to binary, hexadecimal color codes, 0x prefix, programming bases hexadecimal to binary converter free 3tej calcula…
Simplify any whole-number ratio a:b using the greatest common divisor, then scale it by a factor.
Convert any number to scientific notation (a x 10^b) or engineering notation where b is a multiple of 3.
Compute the number of permutations P(n,k) = n! / (n-k)! for any non-negative integers n and k where k is at most n.
Compute the binomial coefficient C(n,k) = n! / (k!(n-k)!), the number of unordered ways to choose k items from a set o…
Compute the Pearson correlation coefficient r between two numeric arrays with r-squared and a strength interpretation.
Compute the chi-square statistic from observed and expected frequencies with degrees of freedom and an approximate p-v…
About math
Math calculators cover the formulas you reach for in school, work, and daily life: fractions, percentages, ratios, exponents, logarithms, factorials, permutations and combinations, GCF and LCM, quadratic equation roots, right triangle and oblique triangle trig, circle and sphere geometry, scientific notation, standard deviation, mean median mode, z-score, t-test, chi-square, ANOVA, linear regression, and correlation.
Use these tools for: homework checking with step-by-step working shown, statistical sample-size planning, A/B test significance testing, geometry questions during DIY projects, unit-circle trig values, and probability calculations for poker or risk modeling. Each tool shows the formula and the substituted values, not just the answer.
Sources: standard textbook formulas (Anton, Stewart, Casella-Berger, Wackerly). Where multiple conventions exist (population vs sample standard deviation, biased vs unbiased estimators), the tool defaults to the most common convention and offers a toggle.
Common use cases
Real scenarios where the math calculators in this category earn their keep.
Sample size for an A/B test
Compute required N per arm given baseline conversion rate, MDE (minimum detectable effect), significance level (α = 0.05 typical), and power (1-β = 0.80 typical).
Standard deviation from raw data
Paste a list of numbers, the tool returns mean, median, mode, range, variance, and both population and sample standard deviation. Quick alternative to running R or pandas.
Right triangle solver
Given any two sides or one side + one angle, solve for the remaining sides and angles using the Pythagorean theorem and basic trig identities.
Combinations and permutations
C(n,k) for picking k from n where order doesn't matter; P(n,k) where order does. Used for lottery odds, hand probabilities, and password-strength estimation.
Quadratic equation roots
Solve ax² + bx + c = 0 by the quadratic formula. Returns real or complex roots, the discriminant, and the vertex.
Key terms
Glossary for the formulas and conventions these tools use.
- Standard deviation
- Square root of variance. Measures spread of a distribution around its mean. Sample SD divides by (n-1); population SD divides by n (Bessel's correction).
- Z-score
- (value - mean) / standard deviation. Number of standard deviations away from the mean. Used for normalization and outlier detection.
- Combination C(n,k)
- Number of ways to choose k items from n without regard to order. C(n,k) = n! / (k! × (n-k)!).
- Permutation P(n,k)
- Number of ways to arrange k items from n where order matters. P(n,k) = n! / (n-k)!.
- GCF / LCM
- Greatest Common Factor (Euclidean algorithm) and Least Common Multiple (LCM(a,b) = a × b / GCF(a,b)).
- Quadratic discriminant
- b² - 4ac in the quadratic formula. Positive = two real roots, zero = one repeated root, negative = two complex conjugate roots.
- p-value
- Probability of observing the data (or more extreme) under the null hypothesis. Below α (typically 0.05) means reject the null.
Frequently asked questions
Short answers to the most common math questions.