What This Calculator Does
The Ideal Egg Boiling Calculator tells you how long to boil an egg to reach your preferred doneness — soft (runny yolk), medium (jammy yolk), or hard (fully set yolk). It then fine-tunes that time for your egg size and your kitchen's altitude, since water boils at a lower temperature in the mountains and needs extra cooking time.
How to Use It
Pick your desired doneness, choose your egg size, and enter your altitude in meters above sea level (use 0 if you are near the coast). The calculator returns the recommended boiling time. For best results, lower eggs into already-boiling water, start your timer immediately, then transfer to an ice bath when done.
The Formula Explained
The estimate is built from three parts: a base time set by doneness (soft = 6 min, medium = 8 min, hard = 11 min), a size adjustment (small −1, medium 0, large +1, jumbo +2 minutes), and an altitude adjustment of roughly 1 extra minute for every 300 meters of elevation. Added together: $$t = t_{base} + \Delta_{size} + \frac{altitude}{300}$$
Worked Example
You want a medium egg, large size, at 600 m altitude. Base time = 8 min, size adjustment = +1 min, altitude adjustment = \(600 / 300 = 2\) min. Total = $$8 + 1 + 2 = 11 \text{ minutes}$$
FAQ
Cold start or boiling water? These times assume you start the timer once eggs are in fully boiling water. A cold-water start adds a few minutes of variable heat-up time.
Why does altitude matter? Water boils cooler at altitude (about 1°C lower per 300 m), so eggs cook more slowly and need extra time.
How do I stop overcooking? Plunge the eggs into ice water right after the timer ends to halt cooking and make peeling easier.
