Egg Boiling Calculator
Exact times for soft, jammy, medium, and hard boiled eggs.
Boiling Time (in already-boiling water)
How to Use This Egg Boiling Calculator
Pick your target doneness, egg size, and whether the eggs are fridge-cold or room temperature, then enter your altitude. The calculator starts from tested base times for large eggs in already-boiling water and adjusts for size, starting temperature, and altitude. Times assume a rolling boil with the eggs lowered in gently; start your timer the moment the last egg goes in.
Bring a pot with enough water to cover the eggs by an inch to a full rolling boil.
Enter your settings above and read the time. Lower the eggs in with a slotted spoon to avoid cracks.
Start the timer immediately and keep the water at a steady boil, not a violent one.
Transfer to ice water the second the timer rings. Peel under running water for the cleanest results.
Base Times and Adjustment Method
The base times come from the consensus across tested recipes: Simply Recipes, Serious Eats style testing, and USDA-adjacent guidance all cluster within a minute of these numbers. Egg size shifts time because heat must reach the yolk center; a jumbo egg's extra mass needs about a minute more. Altitude matters because water boils at 203F at 5,000 feet instead of 212F, so heat transfers slower the whole cook.
Worked Example
Extra-large eggs, straight from the fridge, jammy doneness, at 5,000 feet. Base 7.5 + 1.0 (size) = 8.5 minutes. Altitude adjustment: 5,000 feet is 3,000 feet above the 2,000 threshold, so +15%: 8.5 x 1.15 = 9.8, about 10 minutes. At sea level the same eggs need 8.5 minutes. That two-minute gap is the difference between jammy and chalky at altitude.
Practical Tips for Perfect Eggs
Use the same pot every time; different pots return to a boil at different speeds and change results. Do not overcrowd: eggs should sit in a single layer with water circulating. Add a teaspoon of baking soda to the water if your eggs are very fresh; it raises the pH and helps peeling. Crack the shell all over on the counter and roll gently before peeling under a thin stream of water. For deviled eggs, 11 minutes plus an ice bath gives yolks that mash smoothly.
Boiling-Water Start vs Cold Start
The boiling-water start wins on precision: the timer starts when the eggs hit the water, full stop. The cold start (eggs in cold water, bring to a boil, then cover and rest off heat) is gentler and nearly crack-proof, but timing depends on your stove's heat-up speed. This calculator uses the boiling-water method because it is reproducible across kitchens. If you prefer cold start, use these rest times off heat: 5 minutes soft, 7 to 8 jammy, 11 to 12 hard.
Second worked example: a dozen deviled eggs
Twelve large eggs, straight from the fridge, lowered into already-boiling water: 10 minutes for firm yolks that still slice cleanly. Move them straight into an ice bath for 10 minutes; the cold stops the cooking dead and loosens the shells. Peel under running water, starting at the wide end where the air pocket sits. Halve, pop the yolks, and you have 24 halves. The ice bath is doing double duty here: it prevents the green sulfur ring on the yolks and it makes a dozen eggs peelable in minutes instead of a frustrating half hour.
Why the ice bath is not optional
Two reactions run while a boiled egg sits hot. The yolk keeps cooking from residual heat, sliding from jammy to chalky in about 3 minutes. And iron in the yolk reacts with sulfur in the white, forming ferrous sulfide, the green-gray ring that also smells faintly of sulfur. The ice bath halts both in under a minute. Cold water alone is not enough; without ice the water warms and the reactions continue. Ten minutes in real ice water, then peel or refrigerate. Eggs that skip the bath are the ones with rubbery whites and green yolks.
Peeling science
Fresh eggs peel badly because the white's low pH makes it cling to the inner membrane. As eggs age 7 to 10 days in the fridge, carbon dioxide escapes through the shell, the pH rises, and the white releases cleanly. This is why farm-fresh eggs frustrate and week-old supermarket eggs peel like a dream. Starting in boiling water instead of cold helps too: the heat sets the outer white fast, before it can bond to the membrane. Steaming works the same way and is gentler on large batches. Baking soda in the water is mostly myth; the pH shift is too small to matter.
Boiling mistakes
Crowding the pot drops the water temperature and the eggs cook unevenly; one layer with room to roll is the rule. Starting eggs in cold water and guessing the timing is second; the come-up time varies with every stove, so the minutes are meaningless until the water boils. Skipping the ice bath is third, covered above. Cracking eggs into already-cracked water: a tablespoon of vinegar in the water helps a cracked egg's white set instead of feathering, but it does nothing for intact eggs. And refrigerating unpeeled eggs in the shell keeps them a full week; peeled, they last 2 days in water, changed daily.
A Second Worked Example: High-Altitude Hard-Boiled
At 5,000 feet, water boils at about 203Β°F instead of 212Β°F, and eggs cook slower in the cooler water. Take the sea-level baseline for large eggs: 11 minutes for firm yolks. The altitude adjustment adds roughly 1 minute per 1,000 feet above 3,000, so at 5,000 feet add 2 minutes, giving 13 minutes. Start the timer when the water returns to a full boil after the eggs go in, not when they hit the water, because the temperature dip pauses the cooking.
Check doneness the reliable way: pull one egg at 13 minutes, cool it under running water for 30 seconds, and cut it open. The yolk should be fully set with no translucent center. If it is still jammy, the remaining eggs need 1 to 2 more minutes; egg size and exact altitude vary enough that the first batch is always a calibration run. Write your adjusted time on the fridge and the second batch is automatic.
Carryover Cooking: The Timer Stops, the Egg Doesn't
An egg pulled at exactly 10 minutes is not done cooking. Residual heat keeps driving the yolk toward firm for several minutes after it leaves the pot, which is why eggs timed perfectly and left in a bowl come out overdone. The ice bath is not just about peeling; it is a hard stop on carryover cooking. Two minutes in ice water drops the egg's core temperature fast enough to freeze the texture where the timer left it.
This matters most for soft and jammy eggs, where a 60-second overshoot ruins the texture. For a 6-and-a-half-minute egg, move it to ice water at 6:30 sharp, not 6:45 "when you get to it." For hard-boiled eggs the window is forgiving, 11 versus 12 minutes barely registers, but the ice bath still buys you easy peeling. The rule: the softer the target, the faster the transfer.
Egg Size and Starting Temperature: The Two Adjustments
Recipes assume large eggs, about 57 grams each, straight from boiling water. Medium eggs, around 50 grams, need about 1 minute less; extra-large, around 64 grams, need about 1 minute more. The relationship is roughly linear because heat penetrates at a steady rate: 10 percent more egg mass needs about 10 percent more time, which rounds to a minute at these scales.
Fridge-cold versus room-temperature eggs shift things by about 1 minute as well. A cold egg dropped into boiling water chills the surrounding water more and starts from 38Β°F instead of 68Β°F. If your eggs live in the fridge, which they should in the US, use the cold-egg timing as your baseline and note it. Consistency beats precision here: same egg size, same starting temperature, same pot of water every time, and your personal perfect time emerges within two batches.
The Green Ring: What It Is and How to Dodge It
The gray-green ring around an overcooked yolk is iron sulfide, formed when hydrogen sulfide from the egg white reacts with iron in the yolk at high heat over too much time. It is harmless but ugly, and it signals a chalky, sulfurous yolk. It appears reliably past about 12 to 13 minutes at a full boil for large eggs, which is why the "boil for 20 minutes to be safe" method guarantees it.
Three things prevent it: correct timing, the ice bath, and gentle heat. A hard simmer cooks as fast as a rolling boil once the water is at temperature; the violent boil just bangs the eggs around and cracks shells. Keep the water at a lazy bubble, time it right, shock in ice water, and the yolks stay golden. If the ring appears anyway, the eggs are still fine to eat; slice them for salads where the cross-section hides the evidence.
Frequently Asked Questions
How long do you boil eggs for soft boiled?
Boil large eggs for 6 to 7 minutes in already-boiling water for soft boiled eggs with set whites and runny yolks. Start timing the moment the eggs go in, and move them to ice water immediately when the timer rings.
How long for jammy eggs?
Seven to 8 minutes in boiling water gives jammy eggs: fully set whites with a thick, custardy yolk that is perfect for ramen. Six minutes gives the ultimate jammy egg with a sticky center; 8 minutes firms it further.
How long do you boil eggs to make them hard boiled?
Ten to 12 minutes for large eggs in boiling water gives fully set yolks without the green ring. Ten minutes keeps the yolk creamy at the center; 12 minutes sets it firm for deviled eggs and slicing.
Do you start eggs in cold or boiling water?
Boiling water gives more predictable timing because the clock starts cleanly, and the eggs peel easier. Cold-start (eggs in cold water, then timed after the boil) is gentler and cracks fewer eggs. Pick one method and learn its times.
Why do hard boiled eggs get a green ring around the yolk?
Overcooking. Iron in the yolk reacts with hydrogen sulfide in the white above about 170F, forming green ferrous sulfide. It is harmless but ugly and a little sulfury. Stay at 10 to 11 minutes and ice-bath promptly to avoid it.
How does altitude change egg boiling time?
Water boils cooler at altitude, so eggs cook slower. Add roughly 5% more time per 1,000 feet above 2,000 feet. At 5,000 feet, a 10-minute hard boiled egg needs about 11.5 minutes. The calculator above applies this automatically.
Why are some hard boiled eggs hard to peel?
Very fresh eggs peel worst because their whites are more acidic and grip the membrane. Eggs that are a week or two old peel far easier. The ice bath also helps by shrinking the egg slightly inside the shell.
Can you boil eggs straight from the fridge?
Yes, but add about a minute versus room-temperature eggs, and lower them in gently with a spoon so the thermal shock does not crack the shells. The calculator has a starting-temperature setting for exactly this.
How long do hard boiled eggs last in the fridge?
Up to 7 days in the shell, refrigerated. Peeled eggs last about 5 days stored in water or a sealed container. Write the boil date on the shell with a pencil if you batch cook.
What is the ice bath for?
It stops the cooking instantly so your timing actually means something, and it makes peeling easier. Without it, residual heat keeps cooking the yolk for several minutes past your target. Five minutes in ice water is enough.