Egg Boiling Calculator
Get the exact boiling time based on doneness, egg size, starting temperature, and altitude.
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This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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Select your preferred doneness, egg size, and starting temperature to get the exact boiling time. Here is what each option means:
- Choose your doneness. Soft boiled eggs have a completely runny yolk and a just-set white (6-7 minutes). Medium boiled eggs have a jammy, creamy yolk that holds its shape but is not chalky (9-10 minutes). Hard boiled eggs are fully set throughout with no runniness (12-13 minutes).
- Select your egg size. Large eggs (the most common) are the baseline. Extra-large eggs have a slightly different surface-area-to-volume ratio, so they need about 30 seconds less time.
- Set the starting temperature. Eggs straight from the fridge take about 1 minute longer than eggs at room temperature, because the cold mass takes more time to heat through.
- Enter your altitude if relevant. Water boils at a lower temperature at high altitudes (below 212°F at sea level), which slows cooking. The calculator adds 1 minute for every 2,000 feet above sea level.
- Start your timer. Lower eggs gently into already-boiling water, then start the clock. When the timer ends, transfer immediately to an ice bath to stop cooking.
About Egg Boiling Times
Egg boiling times depend on the thermal physics of heating a dense protein mass from the outside in. The white (albumen) sets between 140-149°F while the yolk sets between 149-158°F. By controlling time, you control how much of the yolk reaches setting temperature. A soft boiled egg only partially heats the yolk; a hard boiled egg heats it fully through.
Starting temperature matters because cold eggs (around 40°F from the fridge) require more energy input before the proteins begin denaturing. Altitude matters because water boils at lower temperatures when atmospheric pressure is reduced: at 5,000 feet, water boils at about 202°F, slowing protein coagulation and requiring more time. An ice bath immediately after cooking is essential because residual heat inside the egg continues cooking the yolk even after removal from the water.
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Frequently Asked Questions
How long do I boil eggs for soft, medium, and hard doneness?
Starting from room temperature large eggs in boiling water: soft boiled is 6-7 minutes (runny yolk), medium boiled is 9-10 minutes (jammy yolk), and hard boiled is 12-13 minutes (fully set yolk and white). Add 1 minute for eggs straight from the fridge. Always transfer to an ice bath immediately after the timer ends.
Does it matter if eggs come from the fridge or are at room temperature?
Yes. A refrigerator-cold egg (about 40°F) starts much further from boiling water temperature than a room-temperature egg (about 68-72°F). The cold egg takes approximately 1 additional minute to reach the same internal temperature as a room-temperature egg. Cold eggs are also slightly more prone to cracking when placed in boiling water, so lower them in gently with a spoon.
Why does altitude affect egg boiling time?
At higher altitudes, atmospheric pressure is lower, which means water boils at a lower temperature. At sea level, water boils at 212°F. At 5,000 feet it boils at about 202°F. Lower boiling temperature means the water cooks the eggs more slowly, requiring additional time. A general rule is to add 1 minute for every 2,000 feet above sea level. Denver, Colorado (5,280 feet) would need about 2-3 extra minutes.
Why do I need to use an ice bath after boiling eggs?
Even after you remove an egg from boiling water, the hot shell and white continue transferring heat to the yolk (carryover cooking). Without an ice bath, a perfectly timed soft boiled egg can overcook to medium or beyond within 60-90 seconds of removal. Plunging the eggs into ice water immediately stops all heat transfer and locks in your target doneness. It also makes peeling easier by causing the egg to contract slightly away from the shell.