# Bridge Rectifier Calculator

URL: https://speedycalculator.com/calculators/physics/bridge-rectifier/
Last updated: 2026-10-30

> The bridge rectifier calculator finds the DC output voltage, current, peak inverse voltage and ripple of a full-wave bridge rectifier, with or without a smoothing capacitor.

## Inputs

- Secondary RMS voltage (V, mV, kV, µV, MV)
- Diode forward drop (V, mV, kV, µV, MV)
- Load resistance (Ω, kΩ, MΩ, mΩ)
- Mains frequency
- Smoothing capacitance (0 = none) (µF, mF, nF)

## Results

- Peak output voltage
- DC output voltage
- DC load current
- Peak-to-peak ripple
- Ripple factor
- Peak inverse voltage per diode

## Formula

```
V_p = √2·V_rms,  V_DC = 2(V_p − 2V_d)/π (no capacitor),  V_ripple ≈ I_DC/(2fC),  PIV = V_p − V_d
```

## Explanation

A bridge of four diodes turns AC into pulsating DC by flipping the negative half-cycles. A capacitor then smooths it into nearly steady DC – the heart of every traditional linear power supply.

### How to use the Bridge Rectifier Calculator

- **Secondary RMS voltage**
- **Diode forward drop**
- **Load resistance**
- **Mains frequency**
- **Smoothing capacitance (0 = none)**

Results update as you type, every field has its own unit menu, and everything is calculated in your browser.

### How it works

Enter the transformer secondary RMS voltage, diode drop, load resistance, mains frequency and the smoothing capacitor (0 for none).

### Inputs explained

FieldWhat to enterSecondary RMS voltageUnits: V, mV, kV, µV, MVDiode forward dropUnits: V, mV, kV, µV, MVLoad resistanceUnits: Ω, kΩ, MΩ, mΩMains frequencyChoose one: 50 Hz, 60 HzSmoothing capacitance (0 = none)Units: µF, mF, nF

### What each result means

- **Peak output voltage** = sqrt(2)×[Secondary RMS voltage] - 2×[Diode forward drop]
- **DC load current** = [DC output voltage]÷[Load resistance]
- **Peak inverse voltage per diode** = sqrt(2)×[Secondary RMS voltage] - [Diode forward drop]

### Example values

How the main result changes when **Secondary RMS voltage** changes and everything else stays at the example values above:

Secondary RMS voltage (V)DC output voltage (V)66.9243911.07051215.21671519.36291823.50912431.8016

## Worked example

Inputs — Secondary RMS voltage: 12 V; Diode forward drop: 0.7 V; Load resistance: 100 Ω; Mains frequency: 50 Hz; Smoothing capacitance (0 = none): 2,200 µF.

Results — Peak output voltage = 15.5706 V; **DC output voltage = 15.2167 V**; DC load current = 0.1522 A; Peak-to-peak ripple = 0.7078 V; Ripple factor = 0.0134; Peak inverse voltage per diode = 16.2706 V.

## Key terms

- **Full-wave rectifier**: Uses both half-cycles of AC.

## FAQ

**Why two diode drops?**
Current always flows through two diodes of the bridge.

**What is the ripple frequency?**
Twice the mains frequency.

**How big should the capacitor be?**
Large enough that ripple is a small fraction of V_DC – roughly I/(2f·V_ripple).

**What is ripple factor?**
AC RMS ripple divided by DC output; 0.483 without filtering.


## Sources

- [OpenStax – University Physics Volume 2](https://openstax.org/details/books/university-physics-volume-2)
- [The Engineering ToolBox](https://www.engineeringtoolbox.com/)