Perfect Egg Timing Calculator
Get exact boiled egg cooking times for soft, medium, and hard results from egg size, starting temperature, and altitude above sea level.
The perfect boiled egg is a matter of precise timing and temperature control. The proteins in egg whites and yolks coagulate at specific temperatures, and controlling how much heat penetrates the egg determines whether you get a runny yolk, a jammy center, or a fully cooked firm yolk.
Egg Protein Temperature Reference
Understanding when egg proteins set helps explain the timing:
- 63°C (145°F): Egg white begins to set slowly
- 71°C (160°F): Egg white is fully set but still tender
- 70°C (158°F): Yolk begins to thicken
- 77°C (170°F): Yolk is fully solid but still moist
- 85°C+ (185°F+): Yolk becomes crumbly, grey-green ring may form
Why Starting Temperature Matters
Eggs taken directly from the refrigerator (typically 4°C / 39°F) take 1–2 minutes longer to cook than eggs at room temperature (20°C / 68°F). Always factor this in to avoid under- or over-cooked yolks.
Altitude Effects
At high altitudes, water boils at lower temperatures, which slows the cooking process. At 2,000 m (6,560 ft), water boils at ~93°C (199°F), and eggs require roughly 1 minute of extra cooking time per 1,000 m of altitude above sea level.
Cooking Time Guidelines (Large Eggs, Sea Level)
| Style | From Room Temp | From Fridge |
|---|---|---|
| Soft boiled (runny white, runny yolk) | 4–5 min | 6–7 min |
| Soft boiled (set white, runny yolk) | 6–7 min | 7–8 min |
| Medium / jammy (set white, jammy yolk) | 9–10 min | 10–11 min |
| Hard boiled (fully set, moist yolk) | 12–13 min | 13–14 min |
| Hard boiled (firm, dry yolk) | 14–15 min | 15–16 min |
Ice Bath After Cooking
Always transfer cooked eggs immediately to an ice water bath for 5 minutes. This stops the cooking process precisely and makes peeling significantly easier. Without this step, carryover heat continues cooking the egg for 1–2 extra minutes.