Cone Surface Area Calculator
Calculate the total and lateral surface area of a cone, with breakdown ratios, unrolled sector angle, and real-world presets for common conical objects.
Calculate the volume, surface area, lateral area, and slant height of a cone. Supports multiple solve modes, unit conversion, and real-world presets.
A cone is one of the most recognizable three-dimensional shapes, featuring a circular base that tapers smoothly to a single point called the apex. Cones appear everywhere in daily life — from ice cream cones and traffic cones to party hats and architectural spires. Understanding how to calculate the volume and surface area of a cone is a fundamental skill in geometry, engineering, and manufacturing.
The volume of a cone equals one-third the volume of a cylinder with the same base and height, expressed as V = ⅓πr²h. This elegant relationship means a cone holds exactly one-third the material of its cylindrical counterpart. The total surface area combines the circular base (πr²) with the curved lateral surface (πrl), where l is the slant height calculated using the Pythagorean theorem: l = √(r² + h²).
This calculator supports three solve modes: given radius and height, given radius and slant height, or reverse-solving height from a known volume and radius. It also includes presets for common real-world cones, a surface-area breakdown with visual ratio bars, and a reference table so you can quickly compare dimensions of familiar conical objects.
Use this when you need the volume of a cone or frustum for fill estimates, hopper sizing, pouring calculations, or geometry practice. It keeps the radius, height, slant values, and derived volume tied together so you can check the dimensions before using the result for material or capacity planning.
Volume: V = ⅓πr²h
Lateral Surface Area: A_l = πrl
Base Area: A_b = πr²
Total Surface Area: A = πr(r + l)
Slant Height: l = √(r² + h²)Result: For solvemode=5, units=10, radius=15, the tool returns the solved cone volume outputs shown in the result cards.
This example uses a realistic input set from the calculator workflow. After entry, the calculator applies the built-in cone volume formulas and reports derived values, checks, and classifications automatically.
Calculate the volume, surface area, lateral area, and slant height of a cone. Supports multiple solve modes, unit conversion, and real-world presets. Use it when you need a repeatable calculation in the math / geometry category and want the setup, result, and supporting values kept together. This is especially helpful when small input changes, unit choices, or rounding decisions can change the final number.
Start by confirming that the inputs match the formula shown on the page. Then compare the main output with the worked example and any secondary values shown by the calculator. If the result will be used in another calculation, keep extra precision until the final step and record the assumptions beside the number.
Treat the result as a calculation aid rather than a substitute for context. For schoolwork, include the formula and substitution steps. For planning, technical, financial, or health-related decisions, verify important numbers against primary records, current rules, or a qualified professional before acting on them.
Last updated:
The volume of a cone is V = ⅓πr²h, where r is the base radius and h is the perpendicular height from the base to the apex.
Use the Pythagorean theorem: slant height l = √(r² + h²), since the radius, height, and slant height form a right triangle.
Lateral area is the curved side surface only (πrl). Total surface area adds the flat circular base (πr²), giving πr(r + l).
This can be proven with calculus (integration of circular cross-sections) or Cavalieri's principle. Three cones fit exactly inside a cylinder of the same base and height.
Yes — first compute the height: h = √(l² − r²), then use V = ⅓πr²h. This calculator's "Radius + Slant Height" mode does this automatically.
1 liter = 1,000 cm³ and 1 US gallon ≈ 3,785.41 cm³. Calculate volume in cm³ first, then divide accordingly.
Calculate the total and lateral surface area of a cone, with breakdown ratios, unrolled sector angle, and real-world presets for common conical objects.
Calculate the volume, surface area, and capacity of a cylinder. Includes fill level, liter/gallon conversion, diameter mode, and presets for common cylinders.
Calculate the volume and surface area of a sphere. Solve from radius, diameter, circumference, surface area, or volume. Includes presets for common spheres like basketballs and Earth.