The Quadrilateral Calculator is an easy-to-use online tool designed to help users calculate the unknown sides, angles, diagonals, perimeter, and area of a quadrilateral—a four-sided polygon. Whether you're working on geometry homework, designing a layout, or simply curious about the properties of a quadrilateral, this calculator simplifies the math and gives you accurate results in just a few seconds.
A quadrilateral can come in many shapes—such as rectangles, trapezoids, parallelograms, and general irregular forms. Depending on what type of quadrilateral you’re working with, it can be difficult to calculate all the missing values manually. This calculator helps by using known mathematical formulas and relationships between angles and sides to solve the full shape based on partial input.
To use the calculator, you simply enter the lengths of three sides (a, b, and c) and two internal angles (β and γ). From these values, the tool calculates the remaining side (d), the other angles (α and δ), both diagonals (e and f), as well as the perimeter and the area of the quadrilateral. You can also choose how many decimal places you want the results to be rounded to for better precision.
This tool is perfect for students learning geometry, teachers preparing lessons, architects sketching simple floor plans, engineers working on technical designs, or anyone who needs fast and accurate quadrilateral calculations without using a calculator or doing the math by hand.
With a clean and straightforward interface, this calculator takes the guesswork out of geometric problem-solving and allows you to visualize and understand the shape you're working with. Just input your known values, click the Calculate button, and view your complete set of results instantly.
Using the Quadrilateral Calculator is simple and requires only a few steps. You don’t need advanced math knowledge—just enter the known values and the calculator will do the rest. Follow these instructions to get started:
To successfully calculate the shape and properties of a quadrilateral, the calculator needs five key inputs. These values form the foundation for determining the unknown side, angles, diagonals, perimeter, and area. Here's what you need to provide:
All five of these values must be filled in before you click the Calculate button. If any of them are missing or incorrect, the calculator will not be able to complete the computation and will show an alert message.
The Quadrilateral Calculator includes an optional setting that allows you to control how your results are displayed. This is especially helpful if you're working on technical tasks or simply prefer results with more (or fewer) decimal places.
This setting affects all calculated values, including sides, angles, diagonals, perimeter, and area. For example, if you choose to round to 2 decimal places, a value like 12.34567 will be displayed as 12.35.
Adjusting the rounding option is completely optional. If you're not sure what to choose, you can leave it at the default setting and still get accurate results suitable for
Once you enter the required values (Side a, Side b, Side c, Angle β, and Angle γ) and click the Calculate button, the Quadrilateral Calculator uses geometric formulas to compute the remaining details of the shape. Here's what the calculator will determine for you automatically:
These results are displayed instantly in their respective fields after calculation. There’s no need for you to solve any equations—the calculator handles all the complex geometry for you.
After using the Quadrilateral Calculator, you’ll see several values automatically filled in. These results give you a complete picture of your quadrilateral’s shape, size, and dimensions. Here’s a simple explanation of what each result means and how it relates to the overall structure:
Each result is rounded based on the setting you selected in the "Round to" menu, making it easier to read or use in your specific project. If any result seems off, double-check your input values to make sure they are accurate and realistic for a quadrilateral shape.
The Quadrilateral Calculator features two main buttons that control how the calculator works. Each button has a specific function to help you either generate results or clear the form.
When you click the Calculate button, the calculator checks that all required inputs are filled in (Side a, Side b, Side c, Angle β, and Angle γ). If everything looks good, it runs the necessary formulas and instantly fills in all the missing values—including the fourth side, angles, diagonals, perimeter, and area. This button is the core of the calculator and must be clicked to see any results.
Clicking the Delete button resets the entire calculator form. All input fields and results will be cleared so you can start fresh. Use this button when you want to perform a new calculation with different values or fix a mistake in your previous input.
These buttons make it easy to use the calculator repeatedly—whether you're working on multiple problems, comparing different shapes, or experimenting with different values.
Here are some frequently asked questions (FAQs) to help you better understand how the Quadrilateral Calculator works and how to get the most out of it.
Certain fields, such as Side d, Angles α and δ, the diagonals, perimeter, and area, are calculated automatically by the tool. These fields are locked (read-only) to prevent accidental changes since they depend on the values you enter.
You can use any consistent unit (meters, centimeters, inches, etc.). Just make sure all side inputs are in the same unit. The output will follow the same unit system.
All angles must be entered in degrees (°), not radians or gradians. This is important for accurate calculations.
The calculator requires five specific inputs: Side a, Side b, Side c, Angle β, and Angle γ. If any of these are missing or invalid (like negative numbers or empty fields), the calculator won’t run and will show an alert asking you to complete the inputs.
Yes. Use the “Round to” dropdown menu to select how many decimal places you want your results rounded to—from 0 up to 15 places.
Yes. The calculator uses standard geometry and trigonometry formulas to ensure accurate results. However, rounding settings and extremely small or large values can affect precision slightly.
Absolutely! The calculator is responsive and works on phones, tablets, and computers for convenience on the go.