You Want Jammy Eggs with Runny Centers. But How Long Do You Boil Them?
A soft-boiled egg with a runny yolk takes a different time than a hard-boiled egg with a fully cooked yolk. Jammy eggs, that creamy, slightly-set-but-still-runny yolk, require precision. Three minutes too short and the yolk is liquidy, three minutes too long and it's fully cooked. You need exact timing, not guesses.
What This Calculator Does
This egg boiling calculator tells you the exact cooking time for any doneness level. You select how many eggs you're cooking, whether they're straight from the fridge or at room temperature, and your desired yolk consistency (soft, jammy, medium, or hard). The calculator shows the exact time to boil them. No more trial and error, just perfectly cooked eggs, every time.
How to Use This Calculator
Select how many eggs you're boiling. Egg count matters because a larger batch takes slightly longer to come to a boil and distribute heat evenly.
Choose whether your eggs are refrigerated or at room temperature. This affects timing, cold eggs take longer to cook through.
Select your desired doneness:
The calculator displays exact boiling time from when the water reaches a rolling boil.
The Formula Behind the Math
Egg cooking time depends on the size of the egg, the starting temperature, and your desired yolk doneness. Large eggs are standard.
Standard boiling times for large eggs (from cold tap water brought to a boil, then start timing):
Starting from room temperature eggs:
Let's work through an example. You have 6 large eggs straight from the fridge and want jammy yolks.
The ice bath is critical. It stops the cooking immediately. Without it, the residual heat continues cooking the yolk, turning jammy eggs hard.
Why ice bath matters:
Hot eggs continue cooking outside the water due to carryover heat. An ice bath stops this instantly. Jammy eggs without an ice bath become hard-boiled as they cool in your kitchen air.
Egg Size and Cooking Time
Extra-large eggs: Add 30 seconds to all times
Medium eggs: Subtract 30 seconds to 1 minute from all times
Extra-small eggs: Subtract 1–2 minutes from all times
Most recipes assume large eggs. If you're using a different size, adjust accordingly. When in doubt, weigh your eggs or use this as your baseline: 1 large egg weighs about 50g.
Water Acidity and Doneness Visibility
White, runny yolk, and yolk color are affected by water pH. In slightly acidic water, whites set faster. This is why some recipes add vinegar or baking soda. You don't need to adjust timing unless you're in extremely hard water (very alkaline). Standard tap water works fine for home use.
Preventing Cracks While Boiling
Eggs crack when cold eggs are submerged directly in boiling water (thermal shock). To prevent this:
Method 1 (recommended): Bring water to boil, then gently add eggs using a spoon. Lower them in slowly so they don't crack.
Method 2: Start eggs in cold water, bring to boil, then follow timing from boiling point.
Method 3: Use an egg piercer to make a tiny hole in the wider (air pocket) end before boiling. This equalizes pressure and prevents cracking.
Method 2 is technically more reliable (it's what commercial kitchens use because it's repeatable). Method 1 is faster if you're in a hurry. Method 3 is extra insurance if you're struggling with cracking.
Altitude Adjustments
At high altitude, water boils at a lower temperature. This means eggs cook more slowly.
High altitude adjustments:
At high altitude, use a boiling water thermometer to verify your water is actually boiling (not just simmering).
Peeling Tips
The ice bath is step one. A 5-minute ice bath makes shells easier to peel.
Peel under running water. The water gets between the shell and egg white, making separation easier.
Start from the wider end. There's an air pocket near the wider end, start cracking there and work your way around.
Use older eggs. Eggs that are 7–10 days old peel much easier than fresh eggs (less than 5 days old). The whites separate from the shell more readily with age.
Tips and Things to Watch Out For
Don't skip the ice bath. Without it, carryover heat keeps cooking the egg. Your "jammy" eggs become hard.
Use a timer. Guessing time is unreliable. Use a kitchen timer and be precise. One minute makes a difference between soft and jammy.
Start timing after water returns to a boil. The time the recipe gives begins when the water reaches a rolling boil, not when you add the eggs.
Cool eggs immediately in ice water. Don't leave them in hot water while you gather ice. They'll keep cooking. Have ice water ready before you start.
Gentle handling after cooking. Hot cooked eggs are delicate. Use a slotted spoon to transfer them to ice water, and handle gently until cooled.
Don't microwave eggs in their shells. Steam builds pressure inside the shell and they can explode. Boil in water or cook scrambled in a microwave-safe dish.
Frequently Asked Questions
Can I boil eggs that are at different temperatures?
It's not ideal. Room temperature eggs cook faster than cold eggs. If you have a mix, use the cold egg timing (longer time) to ensure none are undercooked.
Why do my boiled eggs have a gray ring around the yolk?
That's a reaction between iron in the yolk and sulfur in the white. It's harmless and happens when eggs are overcooked or left to cool slowly. It's cosmetic, not a food safety issue. An ice bath minimizes it.
Can I make soft-boiled eggs without an ice bath?
You can, but they continue cooking as they cool. You'd have to eat them immediately while still hot, or accept harder yolks. The ice bath is the easiest way to achieve perfect results.
How long can boiled eggs sit in the fridge?
About 7 days if kept in their shells. Peeled eggs should be used within a few days. Keep them in an airtight container to prevent them from absorbing odors from other foods.
Can I reheat boiled eggs?
Yes. Slice them, warm gently in hot water (don't boil), and serve. They won't be as visually appealing as fresh-boiled, but they're safe and edible.
Why do some recipes say 8 minutes and others say 10 minutes for jammy eggs?
Variations come from different starting temperatures, egg sizes, and preferences. Some people prefer softer centers than others. 8 minutes is standard; adjust by 30 seconds based on your preference.
Can I cook extra-large eggs the same way as large eggs?
Add about 30 seconds per minute for extra-large eggs. So soft-boiled becomes 6.5–7.5 minutes instead of 6–7 minutes.
Related Calculators
Use our temperature converter if temperatures in this guide are in a unit you don't use. Our serving size calculator helps determine how many eggs to cook per person.