# Crystal Load Cap Calculator > Compute a crystal's load capacitors from the datasheet CL and stray capacitance — the detail that makes (or breaks) the clock. Practice: elettronica Status: Proto v0.1 Tag: Quarzo, Oscillatore, Load Capacitance, Clock, EMC Method, assumptions and limits: Page: --- Tool to size the load capacitors of a crystal oscillator. From the crystal's nominal CL and the PCB+pin stray capacitance you get the two cap values, the nearest E-series value and the resulting error on the effective CL. A wrong value here shifts the frequency and can fail compliance tests. This file is a **descriptor**, not the tool's documentation: it says what the tool computes and by what method, in summary. Formulas, assumptions, validity conditions and limits are in the wiki linked above. The tool runs in the browser at the page given.