Egg Boiling Calculator

How Egg Boiling Time Works

Boiled egg timing depends on egg mass, starting temperature, water boiling point, and the yolk texture you want. Higher altitude lowers boiling temperature and increases cook time. Related tools: Boiling Point at Altitude Calculator and Temperature Converter.

Williams Heat-Diffusion Model

This calculator uses a simplified version of the Williams egg-cooking model:

$$t = m^{2/3} K \ln\left(\frac{T_{\text{egg}} - T_{\text{water}}}{T - T_{\text{water}}}\right)$$

where $m$ is egg mass in grams, $T_{\text{egg}}$ is the starting egg temperature, $T_{\text{water}}$ is boiling point, and $T$ is the target temperature at the white-yolk boundary.

Doneness Targets

Soft eggs target about 65°C, medium about 70°C, and hard eggs about 75°C. Cool eggs in cold water right after cooking to stop carryover heat from over-setting the yolk.