Every formula, geometry, and physics calc you ever needed.
School essentials, unit conversions, algebra + calculus, geometry, statistics, and physics — the math you needed in school plus the math you wish you'd kept.
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Hand-picked starters.
The 2 calculators every student needs.
GPA tracking and grade-needed math — back-solve what you need on the final.
Bigger than one calculator? Follow the flow.
Multi-step paths that string the right math tools together in the order most people actually use them — with your numbers carried from step to step.
Algebra, calculus, and the everyday math.
Percentages, fractions, quadratics, derivatives, integrals, and the matrices + logarithms that come up in real problems.
Percentage
Drag value and percent. The widget computes "X% of Y" and "Y is what % of Z" plus % increase / decrease.
Fraction Calculator
Add, subtract, multiply, divide, and simplify fractions — with decimal equivalents and LCD work shown.
¾ + ½= 1¼ = 1.25Every common unit, instantly.
Length, weight, temperature, volume, speed, pressure, energy, area, and the rare ones you only need once a year.
Length Converter
Drag any length in meters. The widget shows the equivalent in feet, inches, yards, miles, and kilometers in real time.
Temperature Converter
Celsius, Fahrenheit, Kelvin, and Rankine — with the conversion formulas shown live.
100°C = 212°Fwater boilingAreas, volumes, and right-triangle math.
Circles, triangles, polygons, volumes, slopes, and the distance / Pythagorean lookups every geometry student does.
Circle Calculator
Drag the radius. Area, circumference, and diameter update live with the exact + decimal forms.
Triangle Calculator
Solve any triangle with 3 known values — sides + angles + area, with law of sines/cosines work shown.
3-4-5 trianglearea = 6Distributions, p-values, and inference.
Z-scores, confidence intervals, hypothesis tests, sample sizes, regression, and descriptive stats — the AP / college-stats toolkit.
Z-Score
Drag value, mean, and standard deviation. The widget computes z + the corresponding normal-distribution percentile.
Standard Deviation
Compute σ (population) and s (sample) with full work shown — variance, deviations, and SE of the mean.
σ = 14.410-value test setForces, motion, energy, and waves.
Newtonian mechanics, kinematics, energy + work, free-fall, density, and wave equations — the high-school + first-year-college physics toolkit.
Free Fall
Drag the drop height. Fall time and impact velocity update live (ignoring air resistance, Earth gravity 9.8 m/s²).
Force Calculator
Newton's second law solver — find F, m, or a given the other two. Includes weight on Earth and other planets.
F = 19.6 N2 kg @ 9.8 m/s²The math vocabulary, decoded.
Every definition links to the calculator that puts the term to work. Browse the full glossary →
z = (x − μ) / σThe z-score — how many standard deviations a data point sits from the mean. The gateway to every normal-distribution lookup.A = πr²Area of a circle — the most-reached-for geometry formula, from pizza math to pipe cross-sections.% change = (new − old) / old × 100Percent change — the everyday comparison formula behind raises, discounts, and growth rates.Frequently asked questions
Do the math calculators show work, or just the answer?
Every math calculator shows the step-by-step work — formula identification, substitution, simplification, and final answer. The widget shows just the final result; the full calculator (one click away) shows every step. The work is the point; without it, you can't catch your own mistakes when the answer doesn't look right.
What math notation does the site use?
Standard U.S. textbook notation. Exponents as `x²` or `x^2`, square roots as `√x`, fractions as `a/b` or `a÷b`, percentages as `25%` or `0.25`. The Derivative and Integral calculators accept MathJax-like input. Where ambiguity exists (e.g., `log` is base-10 vs `ln` is base-e), the calculator footer clarifies.
Why do the physics calculators ignore air resistance?
For introductory-physics problems, air resistance is usually omitted because it makes the math intractable without numerical methods. The Free Fall, Kinematics, and Velocity calculators all assume vacuum conditions unless you toggle the drag-coefficient option. Air resistance affects real-world results most for low-mass / high-surface-area objects (a feather vs. a hammer).
Z-score vs. T-score — when to use which?
Z-score: when σ (population standard deviation) is known OR sample size n ≥ 30. T-score: when σ is estimated from the sample AND n < 30. The Z-Score widget assumes you know σ; the Hypothesis Test and Confidence Interval calculators let you pick t- or z-based depending on your inputs.
Are the unit conversions exact or rounded?
Exact for SI-base conversions (meters to centimeters, kilograms to grams). For SI-to-US conversions, we use the official conversion factors (1 mile = 1.609344 km exactly, 1 pound = 0.45359237 kg exactly). The displayed value is rounded to 4 significant figures unless you toggle "full precision" in the full calculator.
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