About My Boiled Egg

My Boiled Egg works out how long to boil your egg and how long to cool it, for the doneness you want. It then runs the timer for you, rings when it is time to move the egg, and can alert your phone even when it is locked.

How the times are calculated

Most boiling charts are rules of thumb. My Boiled Egg instead simulates how heat travels from the boiling water through the white and into the yolk. The egg is modelled with a real egg shape and a spherical yolk, using typical values for how fast yolk and white conduct and store heat. The calculator then finds the boiling time at which the centre of the yolk, after the cooling step, reaches the temperature that gives your chosen doneness.

It takes into account the size of the egg, whether it comes from the fridge, your altitude (water boils cooler up high), salt in the water, and how you cool the egg, including the carry-over cooking that continues after the egg leaves the pot.

The page has three levels of detail: Home cook keeps it to a few taps, Chef lets you set exact values, and Scientist shows the full model, with temperature curves inside the egg.

How accurate is it?

The physics is solid, but every egg and every kitchen is a little different. The model assumes typical egg properties, ignores the shell, and assumes the water keeps boiling once the egg is in. The doneness names map to approximate yolk temperatures, and taste is personal. If a result is slightly off for you, adjust the time by 15–30 seconds and keep the rest of your routine the same: the calculator will then be consistent for your eggs.

Contact

Questions, suggestions or a perfectly boiled egg to report? Write to hello@myboiledegg.com.