Estimate capacitance from spacing, area, and dielectric. Review charge, energy, electric field, and force outputs. Use practical units, presets, exports, formulas, and examples easily.
| Case | Area | Gap | εr | Voltage | Capacitance | Charge |
|---|---|---|---|---|---|---|
| Lab air capacitor | 100 cm² | 1 mm | 1.0 | 12 V | 88.54 pF | 1.06 nC |
| PTFE sheet build | 200 cm² | 0.5 mm | 2.1 | 24 V | 743.75 pF | 17.85 nC |
| Glass dielectric pack | 400 cm² | 2 mm | 4.7 | 48 V | 832.29 pF | 39.95 nC |
The calculator uses the ideal parallel plate relation with optional overlap and fringing adjustments.
C = ε0 × εr × Aeff × kf / d
Q = C × V
E = V / d
U = 0.5 × C × V²
σ = Q / Aeff
u = 0.5 × ε × E²
F ≈ 0.5 × ε × Aeff × (V / d)² × kf
Here, ε0 is vacuum permittivity. εr is relative permittivity. Aeff is effective overlap area. kf is the fringing factor. d is plate separation. V is applied voltage. The force relation assumes a constant voltage case and a nearly uniform electric field.
A parallel plate capacitor stores charge between two conductive surfaces. This calculator estimates capacitance from plate area, spacing, and dielectric material. It also computes charge, stored energy, electric field, force, and surface charge density. These outputs help with classroom analysis, quick design checks, and lab planning.
Larger overlap area increases capacitance. More facing surface gives electric charge more room to collect. That means a wider or longer plate set can store more charge at the same voltage. If plates only partly overlap, the effective area becomes smaller. The calculator accounts for that with the overlap percentage input.
Plate separation has a strong effect. Smaller spacing raises capacitance because the electric field forms across a shorter distance. Very small gaps can improve storage, but they also raise field strength. That can increase the risk of dielectric breakdown. The optional dielectric strength check gives a quick safety estimate.
The dielectric sits between the plates. Its relative permittivity changes how much electric flux the capacitor can support. Air, paper, glass, PTFE, mica, and ceramic all behave differently. A higher relative permittivity usually increases capacitance. This is useful when you want more storage without changing the plate size.
Capacitance alone is not always enough. Charge shows how much electric quantity is stored. Stored energy matters in pulse circuits and filter design. Electric field helps evaluate insulation stress. Force matters in actuators and electrostatic experiments. Energy density and surface charge density also improve physical understanding.
This calculator is useful for physics students, electronics learners, and engineers. It supports quick comparisons between materials and dimensions. The unit selectors reduce conversion mistakes. The result table is easy to review, save, and export. That makes the tool practical for reports, lessons, and prototype calculations.
A parallel plate capacitor is a device with two facing conductive plates separated by an insulating gap. It stores electric charge and energy in the electric field formed between those plates.
Capacitance increases when effective plate area grows, the dielectric constant rises, or the separation distance becomes smaller. In practice, spacing and dielectric limits still control how far you can push the design.
Real plates may not line up perfectly. Overlap percentage reduces the active facing area. That gives a more realistic capacitance estimate for sliding plates, misalignment, or partially covered electrode designs.
The ideal equation assumes a uniform field. Real plate edges spread the field outward. A fringing factor lets you slightly adjust the result when edge effects are known or estimated from testing.
No. The force formula is an approximation for a nearly uniform field and constant voltage conditions. It is useful for estimates, but detailed actuator design may require a more advanced field model.
Breakdown voltage is the approximate limit where the insulating material stops blocking current and starts conducting. Exceeding it can damage the dielectric, cause arcing, or produce unreliable capacitor behavior.
Use the units that match your drawing, lab notes, or datasheet. The calculator converts them internally. That reduces errors and makes it easier to compare metric, micro-scale, and inch-based dimensions.
Yes. It is useful for lab setup checks, dielectric comparisons, classroom demonstrations, and quick report preparation. The exported CSV and PDF options also make it easier to save documented calculation results.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.