Capacitance Calculator

Category: Physics
- May 22, 2025
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Calculate the capacitance of various capacitor types and configurations. This calculator supports parallel plate, cylindrical, spherical capacitors and capacitors in series or parallel connections.

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About Capacitance

Capacitance is a measure of a capacitor's ability to store electric charge for a given potential difference (voltage). The SI unit of capacitance is the farad (F), which is equal to one coulomb per volt (C/V).

Parallel Plate Capacitor

A parallel plate capacitor consists of two parallel conductive plates separated by a dielectric material.

  • Formula: C = ε₀εᵣA/d
  • ε₀: Permittivity of free space (8.85 × 10⁻¹² F/m)
  • εᵣ: Relative permittivity (dielectric constant) of the material between plates
  • A: Overlapping area of the plates
  • d: Distance between plates
Cylindrical Capacitor

A cylindrical capacitor consists of two coaxial cylindrical conductors separated by a dielectric material.

  • Formula: C = 2πε₀εᵣL/ln(b/a)
  • L: Length of the cylinders
  • a: Radius of the inner cylinder
  • b: Radius of the outer cylinder
  • ln(b/a): Natural logarithm of the ratio of outer to inner radius
Spherical Capacitor

A spherical capacitor consists of two concentric spherical conducting shells separated by a dielectric material.

  • Formula: C = 4πε₀εᵣab/(b-a)
  • a: Radius of the inner sphere
  • b: Radius of the outer sphere
Capacitors in Series

When capacitors are connected in series, the reciprocal of the equivalent capacitance is equal to the sum of the reciprocals of the individual capacitances.

  • Formula: 1/C_eq = 1/C₁ + 1/C₂ + ... + 1/Cₙ
  • The equivalent capacitance is always less than the smallest individual capacitance
Capacitors in Parallel

When capacitors are connected in parallel, the equivalent capacitance is the sum of the individual capacitances.

  • Formula: C_eq = C₁ + C₂ + ... + Cₙ
Energy Stored in a Capacitor

The energy stored in a charged capacitor is:

  • Formula: E = ½CV²
  • C: Capacitance
  • V: Voltage across the capacitor
Common Dielectric Materials
Material Dielectric Constant (εᵣ) Breakdown Voltage (MV/m)
Vacuum 1.0 -
Air 1.0006 3
Paper 2.0-4.0 16
Polyethylene 2.1 50
Polypropylene 2.2 40
PVC 3.4 14
Mica 5.0 100
Glass 5.0-10.0 14
Ceramic 20-12000 8
Water 80.0 -
Applications of Capacitors
  • Energy Storage: Storing and releasing electrical energy quickly, as in camera flashes
  • Power Conditioning: Smoothing voltage fluctuations in power supplies
  • Signal Coupling/Decoupling: Blocking DC while allowing AC to pass
  • Filters: Creating frequency-selective circuits
  • Tuning: Selecting specific frequencies in radio circuits
  • Timing: Creating time delays in circuits
  • Sensors: Detecting changes in position, pressure, or humidity

Understanding the Capacitance Calculator

The Capacitance Calculator is a handy tool for anyone looking to calculate the capacitance of different types of capacitors. Whether you need to find the capacitance of parallel plate, cylindrical, or spherical capacitors, this calculator has you covered. It also helps you figure out capacitance for capacitors connected in series or parallel. With just a few inputs, you can get quick and accurate results.

How Does It Work?

Using the calculator is straightforward. You start by selecting the type of capacitor you’re working with. This could be parallel plate, cylindrical, spherical, or configurations with multiple capacitors. After that, you'll input key details like the plate area, distance between plates, and dielectric constant. The calculator uses these variables to provide capacitance values.

Why Choose This Calculator?

  • Easy-to-use interface designed for all skill levels.
  • Supports multiple capacitor types and configurations.
  • Provides energy storage calculations based on voltage input.
  • Offers advanced options like decimal places and scientific notation.

Input Requirements Explained

To get accurate results, specific inputs are necessary. For a parallel plate capacitor, you’ll need the plate area, distance between plates, and the dielectric constant. Each of these values can be adjusted for units like meters, centimeters, or millimeters. For cylindrical and spherical capacitors, you'll need measurements on the inner and outer radii, along with the cylinder's length or sphere's radius.

Understanding Capacitance Values

Capacitance is measured in farads (F), which tells you how well a capacitor can store electric charge. The higher the capacitance, the more charge it can hold. This calculator not only gives you the capacitance value but also calculates the energy stored based on the voltage you provide. Knowing this can be important for designing and understanding electrical circuits.

Step-by-Step Calculation Process

The calculator can show the steps taken to arrive at the final capacitance value, which is helpful for educational purposes. You can see how each input affects the output. This feature is great for students or anyone wanting to learn about electrical engineering concepts more deeply. It breaks down complex calculations into manageable steps.

Practical Applications of Capacitance

  • Used in electronics for energy storage, like in camera flashes.
  • Helps smooth out voltage fluctuations in power supplies.
  • Essential for tuning circuits in radios and Other devices.
  • Important in timing circuits and sensors for detecting changes.

Get Started with the Capacitance Calculator

Ready to find out your capacitor’s capacitance? The Capacitance Calculator makes it simple. Just enter your values, choose your capacitor type, and let the calculator do the rest. It's a valuable tool for engineers, students, and hobbyists who want to make precise measurements in their electrical projects.