This tool calculates the cap values C1 and C2 shown in the picture below from the load capacitance (specified in the data sheet) and the stray capacitance

**Calculator**

Enter

- Load Capacitance from the data sheet and
- Stray capacitance (typically 5 pF but a value between 2 pF and 8 pF can be specified)

The calculator will provide values for C1 and C2

**Example Calculations**

Use the recommended load capacitance value from the data sheet. In the following example data sheet it is 8 pF. A stray capacitance value of 5 pF gives C1 = C2 = 6 pF

**Formula for Load Capacitance Calculator**

**C1 = C2 = 2*(C _{load} – C_{stray})**

**Note**

It’s important to accurately calculate or estimate **C _{stray}** for precise tuning of the crystal frequency. If the actual load capacitance does not match the crystal’s specified load capacitance, the oscillator may operate at an off-nominal frequency, leading to potential communication or timing errors in your application.

**Related Posts**

- Use the PPM to Hz calculator to find the frequency error due to error in parts per million