Electronics
Capacitance Calculator
Estimate capacitance using plate area, separation distance, and dielectric constant for classroom and prototype calculations.
Estimate capacitance using plate area, separation, and dielectric.
Parallel-plate capacitance
C = ε₀ εᵣ A / d
ε₀ is the vacuum permittivity (8.854×10⁻¹² F/m). εᵣ is the material’s relative permittivity. Area (A) must be in square meters and distance (d) in meters.
How to use
- Enter plate area and separation distance (the calculator converts centimeters or millimeters to meters).
- Select the dielectric material or provide a custom relative permittivity.
- Review capacitance in farads with microfarad and picofarad conversions.
Example
Input: Area = 25 cm², Distance = 1.2 mm, Dielectric = FR-4 (εᵣ ≈ 4.3)
Output: Capacitance ≈ 0.79 nF
FAQ & notes
Can I model multiple capacitors in series or parallel?
Use the calculated value and combine using 1/C_total = Σ(1/C) for series or sum them directly for parallel arrangements.
Does fringe capacitance affect the result?
This formula assumes large, parallel plates. Edge effects are ignored, which is acceptable for quick estimates.