Geometry Formula Reference
Reference all standard geometry formulas for 2D and 3D shapes with calculators
Embed Geometry Formula Reference ▾
Add this tool to your website or blog for free. Includes a small "Powered by ToolWard" bar. Pro users can remove branding.
<iframe src="https://toolward.com/tool/geometry-formula-reference?embed=1" width="100%" height="500" frameborder="0" style="border:1px solid #e2e8f0;border-radius:12px"></iframe>
Community Tips 0 ▾
No tips yet. Be the first to share!
Compare with similar tools ▾
| Tool Name | Rating | Reviews | AI | Category |
|---|---|---|---|---|
| Geometry Formula Reference Current | 3.8 | 1825 | - | Maths & Science Calculators |
| Exponential Function Calculator | 4.0 | 2883 | - | Maths & Science Calculators |
| 2019 Calculator | 3.9 | 1533 | - | Maths & Science Calculators |
| Clock Duration Calculator | 3.8 | 2972 | - | Maths & Science Calculators |
| Point Slope Form Calculator | 4.1 | 2104 | - | Maths & Science Calculators |
| Roman Numeral Converter | 4.5 | 2547 | - | Maths & Science Calculators |
About Geometry Formula Reference
Every Geometry Formula You Need in One Place
Geometry formulas are one of those things you learn in school, use occasionally for years, and then suddenly need urgently when you are measuring a room, planning a garden, or helping your kid with homework. Was the area of a triangle base times height divided by 2, or was it base times height? How do you calculate the volume of a cylinder again? The Geometry Formula Reference organizes every essential geometry formula in a clear, searchable format so you can find exactly what you need in seconds.
Two-Dimensional Shape Formulas
Starting with the basics: the area of a rectangle is length times width. The perimeter of a rectangle is 2 times (length + width). These are straightforward. The area of a triangle is one-half times base times height. The area of a circle is pi times radius squared (approximately 3.14159 times r squared). The circumference of a circle is 2 times pi times radius, or equivalently pi times diameter. These five formulas alone cover a huge percentage of everyday geometry needs.
Moving to less common shapes: the area of a trapezoid is one-half times (base1 + base2) times height. The area of a parallelogram is base times height (not base times side - height is the perpendicular distance). The area of an ellipse is pi times the semi-major axis times the semi-minor axis. The area of a regular polygon with n sides is (1/4) times n times s squared times cotangent(pi/n), where s is the side length - which is why people look up polygon formulas rather than memorizing them.
Three-Dimensional Shape Formulas
For solid shapes, you typically need both surface area and volume. The volume of a rectangular prism (box) is length times width times height. Its surface area is 2(lw + lh + wh). The volume of a cylinder is pi times radius squared times height. Its surface area is 2 times pi times r times (r + h). The volume of a sphere is (4/3) times pi times radius cubed. Its surface area is 4 times pi times radius squared.
Less common but frequently needed: the volume of a cone is (1/3) times pi times radius squared times height. The volume of a pyramid is (1/3) times base area times height. The volume of a torus (donut shape) is 2 times pi squared times R times r squared, where R is the distance from the center of the torus to the center of the tube, and r is the radius of the tube.
Coordinate Geometry Formulas
Working with points on a plane requires its own set of formulas. The distance between two points (x1, y1) and (x2, y2) is the square root of [(x2-x1) squared + (y2-y1) squared] - the Pythagorean theorem in coordinate form. The midpoint is ((x1+x2)/2, (y1+y2)/2). The slope of a line through two points is (y2-y1)/(x2-x1). The equation of a line in slope-intercept form is y = mx + b, where m is the slope and b is the y-intercept.
Angle and Trigonometry Formulas
Geometry and trigonometry are deeply connected. The sum of interior angles of an n-sided polygon is (n-2) times 180 degrees. Each interior angle of a regular polygon is [(n-2) times 180] / n degrees. The arc length of a circle sector is radius times angle (in radians). The area of a sector is (1/2) times radius squared times angle (in radians). For right triangles, sine = opposite/hypotenuse, cosine = adjacent/hypotenuse, and tangent = opposite/adjacent.
Why a Reference Is Better Than Memorization
Unless you use geometry formulas daily, trying to memorize all of them is a losing battle. There are simply too many, and confusing similar formulas (like area of a circle vs. circumference, or volume of a cylinder vs. volume of a cone) leads to errors that are hard to catch. A reliable geometry formula reference lets you verify the formula before using it, which is exactly what professionals do. Engineers, architects, and scientists all keep reference materials handy - there is no shame in looking things up when accuracy matters.
Practical Applications
Home improvement: Calculating paint coverage (wall area), flooring quantities (floor area), concrete volume for a patio, or fence material for a circular garden bed. Academic work: Solving geometry problems, checking calculus results, and preparing for standardized tests. Professional use: Architects computing building volumes, engineers sizing components, and landscapers estimating material quantities.
The Geometry Formula Reference is designed to be the quickest path from question to answer for any standard geometry calculation. Browse by shape, search by formula type, and get back to your project with confidence that your numbers are right.