Skip to main content

Parallel Plate Capacitance Calculator

Estimate capacitance of parallel plates: C = ε0 εr A / d. Default 0.01 m² area, 1 mm separation, εr = 1 uses vacuum permittivity. Informational lab math only.

Rated 4.7 out of 5 based on 371 reviews

Results

How to compute parallel plate capacitance

  1. Enter plate area and pick m², cm², mm², or in².
  2. Enter separation and pick a length unit. Default gap is 1 mm.
  3. Set relative permittivity εr. Use 1 for air or vacuum approximation.
  4. Read capacitance in pF and µF. Nothing is uploaded.

Parallel plate capacitor

C = ε0 εr A / d

Epsilon zero8.8541878128×10⁻¹² F/m used in the engine
AreaOverlapping plate area after unit conversion
SeparationDistance d between plates
Epsilon rRelative permittivity of the dielectric
Ideal modelUniform field, no fringing correction
ApprovalInformational. Not a part selector.

Parallel plate formula

C = ε0 εr A / d. With A = 0.01 m², d = 1 mm, and εr = 1, C is about 88.5 pF before fringing. Real plates need edge corrections this page skips.

Relative permittivity

εr is 1 for vacuum, higher for ceramics and plastics. Type the material value you have from a datasheet, not a guess for safety clearance.

Lab vs catalog parts

Catalog capacitors include ESR, tolerance, and package limits. This URL is the textbook parallel-plate geometry, not a BOM tool.

Limits

No fringing, no breakdown voltage check.

The formula runs in this tab. CZNull does not receive the numbers.

Informational only. Not wiring, code, or manufacturer approval. See the disclaimer.

What capacitance for 0.01 m² plates 1 mm apart in air?
About 88.5 pF using C = ε0 A / d with εr = 1. The page prints more digits.
Which εr should I use for air?
Use 1 as a vacuum approximation. Humid air differs slightly; this page does not model humidity.
Can I enter area in square inches?
Yes. Pick in² in the area unit list and the engine converts to square meters internally.
Does the page correct for fringing fields?
No. Fringing raises real C slightly when d is not tiny compared to plate size.
How do I find charge on the plates?
Multiply C by voltage on the capacitance-to-charge page after you know C.