Potential Difference Across Each Capacitor Calculator

Example Data Table

Formula Used

Series Capacitors

Equivalent capacitance is calculated as:

1 / Ceq = 1 / C1 + 1 / C2 + 1 / C3 ...

The same charge flows on each capacitor:

Q = Ceq × Vtotal

Potential difference across each capacitor is:

Vi = Q / Ci

Parallel Capacitors

Equivalent capacitance is calculated as:

Ceq = C1 + C2 + C3 ...

Each capacitor has the same potential difference:

Vi = Vtotal

Charge on each capacitor is:

Qi = Ci × Vtotal

Energy Stored

Stored energy is calculated as:

E = 1 / 2 × C × V²

How to Use This Calculator

Enter each capacitor value in the input box.

Select the correct capacitance unit.

Choose series or parallel connection.

Select whether you know total voltage or total charge.

Enter tolerance, voltage rating, and design margin when needed.

Press calculate to view voltage, charge, energy, and warnings.

Use the CSV or PDF button to save your results.

Understanding Capacitor Potential Difference

Why Voltage Division Matters

Capacitors do not always share voltage equally. The answer depends on the circuit arrangement. In a parallel circuit, each capacitor is connected across the same two nodes. Because of that, every capacitor has the same potential difference as the source. The charge can change, but the voltage remains equal. Larger capacitors store more charge at the same voltage.

Series Behavior

A series circuit works differently. The same charge appears on every capacitor plate pair. The applied voltage divides between the capacitors. Smaller capacitors receive a larger share of the voltage. This is important in high voltage circuits. One weak part can be overstressed even when the total source voltage seems safe.

Equivalent Capacitance

Equivalent capacitance gives one replacement value for the full group. For parallel capacitors, the values add directly. For series capacitors, the reciprocal values add. This makes the final series equivalent smaller than the smallest capacitor. The calculator uses this value to find charge and voltage drop.

Charge and Energy

Charge shows how much electric quantity is stored. Energy shows how much work is held in the electric field. Both values help compare circuit stress. A capacitor with a high voltage may store significant energy, even when its capacitance is modest. This can affect safety, discharge time, and component selection.

Design Checks

Real capacitors have voltage ratings and tolerance limits. A rating should not be treated as a target. Designers often keep voltage below a chosen margin. This calculator compares each result with the entered rating and margin. It also shows a tolerance range for capacitance. These checks help during lessons, lab planning, troubleshooting, and early design review.

Practical Notes

Always confirm the real circuit layout before using results. Mixed capacitor networks may need step by step reduction before entry. For polar capacitors, also check polarity. For high voltage systems, use proper discharge tools and safe procedures. The calculator gives mathematical support, but final hardware decisions need rated parts and careful testing.

FAQs

1. What does potential difference across a capacitor mean?

It means the voltage measured between the two terminals of that capacitor. This value shows how strongly the electric field is established across its plates.

2. Do capacitors in parallel have the same voltage?

Yes. In a parallel connection, each capacitor is connected across the same two nodes. Therefore, each capacitor has the same potential difference.

3. Do capacitors in series have the same voltage?

No. In series, the same charge appears on each capacitor. Voltage divides according to capacitance. Smaller capacitance usually receives larger voltage.

4. Why does a smaller series capacitor get more voltage?

For a fixed charge, voltage equals charge divided by capacitance. When capacitance is smaller, the calculated voltage becomes larger.

5. What is equivalent capacitance?

Equivalent capacitance is a single value that replaces a capacitor group. It helps calculate total charge, voltage division, and stored energy.

6. Can I enter capacitor values in different units?

This version uses one selected unit for all entered capacitor values. Convert values first when your circuit uses mixed units.

7. What does the voltage rating warning mean?

It compares calculated capacitor voltage with the rating and selected design margin. A warning means the capacitor may be unsuitable for that condition.

8. Is this calculator suitable for mixed networks?

Use it after reducing mixed networks into clear series or parallel groups. Complex networks may require several calculation steps.