- Volume Calculator
- Area Calculator
- Perimeter Calculator
- Surface Area Calculator
- Circle Calculator
- Rectangle Calculator
- Triangle Calculator
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Right Triangle Area CalculatorCalculate the area of a right triangle from its two legs using A = ½·a·b. Also returns hypotenuse and perimeter instantly.
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Regular Hexagon Area CalculatorCalculate the area of a regular hexagon from its side length using A = (3√3/2)s². Also returns perimeter and apothem instantly.
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Triangle Area CalculatorCalculate the area of a triangle from its base and height using A = ½·b·h. Fast, free, and accurate for any unit of measurement.
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Square Area CalculatorCalculate the area of a square instantly with A = s². Enter the side length and get area, perimeter, and diagonal in seconds.
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Circle Area CalculatorCalculate the area of a circle instantly with A = πr². Enter the radius to get area, diameter, and circumference in seconds.
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Pounds to Gallons Calculator (Water)Convert pounds of water to US gallons instantly. Enter the weight in pounds and get the volume using the standard 8.34 lb per gallon factor.
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Slope Percentage to Degrees CalculatorConvert a slope percentage (grade) to degrees instantly. Enter the percent grade and get the slope angle in degrees and radians.
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Circle Area and Circumference CalculatorCalculate a circle's area, circumference, radius, and diameter from any one known value using A = πr² and C = 2πr. Fast and accurate.
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Water Tank Volume CalculatorCalculate water tank capacity in liters, US & UK gallons, and cubic meters. Works for cylindrical and rectangular tanks using simple dimensions.
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Triangle Classification CalculatorClassify a triangle as acute, right, or obtuse from its three side lengths by comparing the square of the longest side to the sum of the other two squared.
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SOHCAHTOA CalculatorFree SOHCAHTOA calculator. Enter a right-triangle angle and one side to solve the opposite, adjacent, and hypotenuse plus sin, cos, and tan.
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Law of Cosines Third Side CalculatorFind the third side of a triangle from two sides and the included angle (SAS) using the Law of Cosines: c = √(a² + b² − 2ab·cos C).
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Height of a Triangle from Area and Base CalculatorFind the height of a triangle from its area and base length. Uses h = 2 × Area / base. Fast, free, and works with any units.
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Roof Pitch Angle CalculatorCalculate roof pitch angle in degrees from rise and run. Also gives x-in-12 pitch, slope length and slope percentage for any roof or ramp.
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Radius from Diameter CalculatorFind the radius of a circle from its diameter instantly. Enter any diameter and this calculator returns the radius using r = d/2.
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Radius from Area CalculatorCalculate the radius of a circle from its area using r = √(A/π). Also returns diameter and circumference instantly. Free online geometry tool.
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Diameter from Circumference CalculatorFind a circle's diameter from its circumference using d = C / π. Instantly get diameter, radius, and area for any circumference value.
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TV Screen Size CalculatorCalculate a TV or monitor's actual width, height and screen area from its diagonal size and aspect ratio (e.g. 16:9). Free, instant, accurate.
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Rectangular Prism Volume CalculatorCalculate the volume of a rectangular prism (cuboid) instantly with length × width × height. Also shows surface area. Free and easy to use.
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Cubic Feet of a Rectangle (Box) CalculatorCalculate the cubic feet (volume) of a rectangular box from its length, width and height in feet. Get instant ft³, yd³ and in³ results.
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Square Meters of a Rectangle CalculatorCalculate the area of a rectangle in square meters instantly. Enter length and width in meters to find m² area plus the perimeter.
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Rectangle Aspect Ratio CalculatorFind the aspect ratio of any rectangle from its width and height. Reduces to the simplest integer ratio (e.g. 1920×1080 = 16:9) plus a decimal ratio.
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Gallons to Liters ConverterConvert gallons to liters instantly. Supports US gallons (3.785411784 L) and UK/Imperial gallons (4.54609 L) with exact conversion factors.
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Volume of a Cylinder CalculatorCalculate the volume of a cylinder instantly from its radius and height using V = πr²h. Also shows base area and total surface area.
