Geometry Calculators

Welcome to our collection of free online geometry calculators. Calculate area, circumference, volume, surface area, and slope conversions instantly. All tools work on any device and include step-by-step explanations.

⭕ Circle Calculators

Calculate area, circumference, diameter, and radius from any known circle property.

  • Circle Calculator Hub

    Calculate any circle property (area, circumference, diameter, radius) from another with formulas and step-by-step explanations.

  • Circle Area Calculator

    Find the area of any circle using its radius, diameter, or circumference. Formula: A = π × r².

  • Circle Circumference Calculator

    Calculate the circumference (perimeter) of any circle from its radius, diameter, or area. Formula: C = 2 × π × r.

📐 Shape Calculators (2D & 3D)

Calculate area and perimeter for 2D shapes, or volume and surface area for 3D objects.

📏 Slope & Grade Converters

Convert between degrees, percent slope, rise/run ratios, and elevation grade measurements.

  • Degrees to Percent Slope Calculator

    Convert angles in degrees to percent slope (grade) and back. Learn how to calculate slope percentage from angle measurements.

  • Elevation Grade & Slope Calculator

    Convert between degrees, percent slope, rise/run ratios, inches per foot, and mm per meter. Perfect for construction, drainage, and accessibility calculations.

Frequently Asked Questions

What geometry calculators are available?

CoolConversion offers free geometry calculators for circles (area, circumference, diameter, radius), 2D shapes (area and perimeter for squares, rectangles, triangles, trapezoids), 3D objects (volume and surface area for cubes, spheres, cylinders, cones), and slope/grade conversions (degrees ↔ percent slope, elevation grade).

How do I calculate the area of a circle?

The area of a circle is calculated using the formula A = π × r², where r is the radius. Our Circle Area Calculator accepts radius, diameter, or circumference as input and instantly computes the area with step-by-step explanation.

What is the difference between slope percent and slope degrees?

Slope in degrees measures the angle of inclination (0° = flat, 45° = half-vertical, 90° = vertical). Slope in percent represents rise over run × 100. A 45° slope equals 100% grade because the rise equals the run. The formula to convert is: percent = tan(degrees) × 100.

How do I calculate the volume of a cylinder?

The volume of a cylinder is V = π × r² × h, where r is the radius of the base and h is the height. Use our 3D Shapes Calculator to compute volume and surface area for cylinders, spheres, cubes, cones, and more.

Are these geometry calculators free?

Yes, all geometry calculators on CoolConversion are completely free. No registration, subscriptions, or hidden fees. All tools work on desktop, tablet, and mobile devices.

  • Math Calculators — Percentage, fractions, algebra, prime numbers, and more
  • Area Converter — Convert between square meters, acres, hectares, and more area units
  • Volume Converter — Convert between liters, gallons, cubic meters, and more
  • Angle Converter — Convert between degrees, radians, gradians, and turns